How do i solve 5x^2-20x=0?

x = 0

x = 4

good luck

1st solution (x = 0):
= 5x² - 20x
= x(5x - 20)

2nd solution:
5x - 20 = 0
5x = 20
5x/5 = 20/5
x = 4

Answer: x = 0, 4

Checking:
5(4²) = 20(4)
5(16) = 80
80 = 80

5x^2 - 20x = 0 (factor out 5x)
5x(x - 4) = 0 (zero-product property)
5x = 0 or x - 4 = 0
x = 0 or x = 4 <===ANSWER

Factor

5x(x-4)=0

x=0 or x=4

This called Quadratic Equation.
You can use quadratic formula or just simplify it.

Simplify:
5x^2 - 20x = 0
First factor it:
x(5x - 20) = 0
then divide x at both side which will cancel x at the left side and 0/x is 0
you got:
5x - 20 = 0
then + 20 at both side, and you got:
5x - 20 + 20 = 0 + 20
or
5x = 20
finally, divide by 5 at both side
x = 20/5
x = 4

The second method is to use quadratic formula which suitable for more complex equation.
http://en.wikipedia.org/wiki/Quadratic_equation

Notice that both terms on the LHS contain a factor of 5x. So, express the equation as:

(5x)(x - 4) = 0

Now, in order for the LHS to equal 0, either (5x) or (x - 4)--or both--must equal 0.

5x = 0
x = 0

x - 4 = 0
x = 4

So, there are two possible solutions for x: x = 0, x = 4 ∎

( 5 x ) ( x - 4 ) = 0

x = 0 , x = 4

5x^2 - 20x = 0
5x(x - 4) = 0
x(x - 4) = 0

x = 0

x - 4 = 0
x = 4

∴ x = 0, 4

5x^2 - 20x = 0
x(5x-20) = 0

x is either 0 or 4.