Answer:
45.8
Step-by-step explanation:
We need to find the surface area for this entire figure!
We can see that this is a pyramid here - we must find the area of the 3 triangles and the base triangle at the bottom.
The 3 triangles building up the pyramid are all equal to each other.
To find the area of a triangle, use 

Round to the nearest tenth: 45.75 -> 45.8
40/x=100/190 40/x=100/190
(40/x)*x=(100/190)*x
40=0.526315789474*x
(0.56315789474) to get x
40/0.536315789474=x
76=x
x=76 now we have 190% of 76
So you have to subtract 115 from 15. Then you divide that number by 5 for each relative. That should give you your answer....$20
The 'x' in x^2-7x-30=0 is 4.