Answer:
x=11
Step-by-step explanation:
The sum of the angles of a triangle is 180
We know the angle with a box is 90
90 + 5x-2 + 3x+4 = 180
Combine like terms
8x +92 = 180
Subtract 92 from each side
8x+92-92 = 180-29
8x = 88
Divide each side by 8
8x/8 = 88/8
x = 11
