Isolating Variable Math Example 3

Follow the full solution, then compare it with the other examples linked below.

Example 3

medium

Solve for y: 3(2y - 4) + 5 = 2y + 9

Solution

1
Distribute the 3: $6y - 12 + 5 = 2y + 9$ .
2
Combine like terms on the left: $6y - 7 = 2y + 9$ .
3
Subtract $2y$ from both sides: $4y - 7 = 9$ . Add 7 to both sides: $4y = 16$ . Divide by 4: $y = 4$ .

Answer

y = 4

When an equation has parentheses and variables on both sides, first distribute, then combine like terms, and finally use inverse operations to isolate the variable. Check: