# Question 6625: Both Equation Sides after a Common Shift

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This teaching derivation has second-context AI mathematical and bilingual semantic review, limited to the model and assumptions stated in this question. It has no human review or new Lean proof and does not promote the original question or MKO to Canonical truth.

R0012-06625 · q-20261010-advance-20261014-r03-equation-0100



## Original question and givens

Over Q, L=(1)x+(-24), R=(-1)x+(25), x=24/2, common added quantity e=-1. Give (original L−R, L+e, R+e, shifted difference, are the shifted sides equal?). Use exact reduced fractions with positive denominators, retaining /1 for integers.


- G001 — Over Q, L=(1)x+(-24), R=(-1)x+(25), x=24/2, common added quantity e=-1. Give (original L−R, L+e, R+e, shifted difference, are the shifted sides equal?). Use exact reduced fractions with positive denominators, retaining /1 for integers.





## Definition and scope

Use the original question domain, assumptions and cited MKO definitions. This item has second-context mathematical and bilingual review, with the model, answer and every arithmetic step independently recomputed from the original parameters; the source question remains a candidate.


- [mko-equation](https://ocme.evemisslab.com/en/mko/mko-equation/)





## Step-by-step derivation

S001 · impliesBefore

common rational domain with original equation definitions

After

evaluate/classify the given model without enlarging its original domain

Conditions: none

Original definedness precedes substitution and transformations.Check the declared model,not arbitrary equation solving inferred from cross multiplication or one-point values.

Step identifiers and dependenciesRule: original_rational_equation_scope · Uses: G001





S002 · calculationBefore

original left numerator linear product := mul(1, 12)

After

original left numerator linear product = 12

Conditions: none

Substitute the specified x into this side's coefficient product.

Step identifiers and dependenciesRule: exact_rational_arithmetic · Uses: G001, S001





S003 · calculationBefore

original left numerator affine value := sum(12, -24)

After

original left numerator affine value = -12

Conditions: none

Then add this side's own constant,not the other side's.

Step identifiers and dependenciesRule: exact_rational_arithmetic · Uses: G001, S002





S004 · calculationBefore

original right linear product := mul(-1, 12)

After

original right linear product = -12

Conditions: none

Substitute the specified x into this side's coefficient product.

Step identifiers and dependenciesRule: exact_rational_arithmetic · Uses: G001, S003





S005 · calculationBefore

original right affine value := sum(-12, 25)

After

original right affine value = 13

Conditions: none

Then add this side's own constant,not the other side's.

Step identifiers and dependenciesRule: exact_rational_arithmetic · Uses: G001, S004





S006 · calculationBefore

original L−R := sub(-12, 13)

After

original L−R = -25

Conditions: none

Record the original difference of the two sides first.

Step identifiers and dependenciesRule: exact_rational_arithmetic · Uses: G001, S005





S007 · calculationBefore

left plus common e := sum(-12, -1)

After

left plus common e = -13

Conditions: none

Add the same defined rational e to the left.

Step identifiers and dependenciesRule: exact_rational_arithmetic · Uses: G001, S006





S008 · calculationBefore

right plus common e := sum(13, -1)

After

right plus common e = 12

Conditions: none

Add the identical e to the right,not another constant.

Step identifiers and dependenciesRule: exact_rational_arithmetic · Uses: G001, S007





S009 · calculationBefore

shifted two-side residual := sub(-13, 12)

After

shifted two-side residual = -25

Conditions: none

Subtracting cancels the two copies of e and must recover the original difference.

Step identifiers and dependenciesRule: exact_rational_arithmetic · Uses: G001, S008





S010 · impliesBefore

original difference=-25;shifted difference=-25

After

shifted equality=No

Conditions: none

Adding e to both sides is reversed by subtracting e from both sides,so it preserves equality on the common defined rational domain.

Step identifiers and dependenciesRule: common_shift_reversible_equality · Uses: G001, S009









## Reverse checks


- S010 · premise_and_result_audit — Subtract the same e from both sides to recover the original equation without enlarging its domain.
- S009 · premise_and_result_audit — Recompute shifted two-side residual with exact rational arithmetic, not rounded decimals.
- S008 · premise_and_result_audit — Recompute right plus common e with exact rational arithmetic, not rounded decimals.
- S007 · premise_and_result_audit — Recompute left plus common e with exact rational arithmetic, not rounded decimals.
- S006 · premise_and_result_audit — Recompute original L−R with exact rational arithmetic, not rounded decimals.
- S005 · premise_and_result_audit — Recompute original right affine value with exact rational arithmetic, not rounded decimals.
- S004 · premise_and_result_audit — Recompute original right linear product with exact rational arithmetic, not rounded decimals.
- S003 · premise_and_result_audit — Recompute original left numerator affine value with exact rational arithmetic, not rounded decimals.
- S002 · premise_and_result_audit — Recompute original left numerator linear product with exact rational arithmetic, not rounded decimals.
- S001 · premise_and_result_audit — Check against the original data and this step's premises; a one-way implication is not an equivalence.





## Result

(-25/1, -13/1, 12/1, -25/1, No)

The full substitutions and premise checks give the original answer; source identity,format and status are unchanged.





## This question review and source binding

Review date: 2026-10-26

Original questions, answers, step expressions, numeric ASTs and historical records are retained. Source candidate labels remain historical and are not overwritten as formal proof.

Source hashes and review receipts
- input commit: 0f7be61e2c22317a4075561dc822c87d881a50db
- original question SHA-256: 18c1e0cccfeaaff72fb30e7d668822f2ba5bbd2e662238159747f4d7aa2098b9
- candidate record SHA-256: 5002b65a6f4e52d22d2a4d861c3e8f74b19e6ba6639129fa916d56b15d711a30
- semantic review receipt SHA-256: 90dbc494b2d34ef51f412dcff63cfcc1a2215d038bff71f38f5dded4c64faf00
- question-first witness SHA-256: b72a3b8bcf10f584396e0dd5198c657b0934a71864e5a3fa6321d7a613aef9f9
- Lean: NOT_RUN · human review: NOT_PERFORMED

[Same-source full JSON](https://ocme.evemisslab.com/data/question-derivations/questions/q-20261010-advance-20261014-r03-equation-0100.json)




