4(4.15y)*(5.25y)=852.15

Solution for 4(4.15y)*(5.25y)=852.15 equation:

Simplifying
4(4.15y)(5.25y) = 852.15

Remove parenthesis around (4.15y)
4 * 4.15y(5.25y) = 852.15

Remove parenthesis around (5.25y)
4 * 4.15y * 5.25y = 852.15

Reorder the terms for easier multiplication:
4 * 4.15 * 5.25y * y = 852.15

Multiply 4 * 4.15
16.6 * 5.25y * y = 852.15

Multiply 16.6 * 5.25
87.15y * y = 852.15

Multiply y * y
87.15y2 = 852.15

Solving
87.15y2 = 852.15

Solving for variable 'y'.

Move all terms containing y to the left, all other terms to the right.

Divide each side by '87.15'.
y2 = 9.777969019

Simplifying
y2 = 9.777969019

Take the square root of each side:
y = {-3.126974419, 3.126974419}