Exercise 7 Page 8

To solve the given equation for y, we need to isolate it by adding 4 to both sides of the equation. We want to add 4 because subtraction and addition are inverse operations — they cancel each other out. This is allowed by the Addition Property of Equality.

y-4=3

AddEqn

LHS+4=RHS+4

y-4+4=3+4

AddTerms

Add terms

y=7

We will check our solution by substituting this result back into the original equation and simplifying. If doing so results in an identity, our solution is correct.

y-4=3

Substitute

y= 7

7-4? =3

SubTerm

Subtract term

3=3 ✓

Since substituting y=7 resulted in an identity, our solution is correct.