-35x^2-140+420=0

Solution for -35x^2-140+420=0 equation:

Simplifying
-35x2 + -140 + 420 = 0

Reorder the terms:
-140 + 420 + -35x2 = 0

Combine like terms: -140 + 420 = 280
280 + -35x2 = 0

Solving
280 + -35x2 = 0

Solving for variable 'x'.

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

Add '-280' to each side of the equation.
280 + -280 + -35x2 = 0 + -280

Combine like terms: 280 + -280 = 0
0 + -35x2 = 0 + -280
-35x2 = 0 + -280

Combine like terms: 0 + -280 = -280
-35x2 = -280

Divide each side by '-35'.
x2 = 8

Simplifying
x2 = 8

Take the square root of each side:
x = {-2.828427125, 2.828427125}