The surface area of a rectangular prism is always:
A=2(xy+xz+yz), where x, y, and z are the three dimensions of the prism.
A=2(50*90+50*3.5+90*3.5)
A=2(4500+175+315)
A=2(4990)
A=9980 mm^2
These angles are vertical angles meaning that they are equal to each other. Here is the equation for this problem:
x + 40 = 3x
Combine like terms
(x-x) + 40 = 3x - x
40 = 2x
Isolate x
40/2 = 2x/2
x = 20
Hope this helped!
I’m not for sure of the answer but i do know that the two subtractions in the middle would turn into a + and i think you add the -5/8 + 3/10