Answer:
x = 10
Step-by-step explanation:
the area of a square = s² ( s is the side length )
s² = (4x + 3)² ( take the square root of both sides )
s = [tex]\sqrt{(4x+3)^2}[/tex] = 4x + 3
perimeter = 4s = 172, that is
4(4x + 3) = 172 ( distribute left side )
16x + 12 = 172 ( subtract 12 from both sides )
16x = 160 ( divide both sides by 16 )
x = 10