Respuesta :

mbh292
Write the equation: x + 42 + 30 = 131

Combine like terms: x + 72 = 131

Subtract 72 from both sides: x = 59
Hello!

The perimeter is all of the sides added up. We can write this equation below.

42+30+x=131

We subtract 30 and 42 from both sides.

x=131-30-42
x=131-72
x=59

Therefore, we have x=59.

I hope this helps!