5.) 12y - 5 + 8y + 7 = 42

Explanation:

Step1: Combine like - terms

$(12y + 8y)+(-5 + 7)=42$ $20y+2 = 42$

Step2: Subtract 2 from both sides

$20y+2-2=42 - 2$ $20y=40$

Step3: Divide both sides by 20

$\frac{20y}{20}=\frac{40}{20}$ $y = 2$

Answer:

$y = 2$