0=-7x^2+21x+28

Simple and best practice solution for 0=-7x^2+21x+28 equation. Check how easy it is, and learn it for the future. Our solution is simple, and easy to understand, so don`t hesitate to use it as a solution of your homework.

If it's not what You are looking for type in the equation solver your own equation and let us solve it.

Solution for 0=-7x^2+21x+28 equation:


Simplifying
0 = -7x2 + 21x + 28

Reorder the terms:
0 = 28 + 21x + -7x2

Solving
0 = 28 + 21x + -7x2

Solving for variable 'x'.

Combine like terms: 0 + -28 = -28
-28 + -21x + 7x2 = 28 + 21x + -7x2 + -28 + -21x + 7x2

Reorder the terms:
-28 + -21x + 7x2 = 28 + -28 + 21x + -21x + -7x2 + 7x2

Combine like terms: 28 + -28 = 0
-28 + -21x + 7x2 = 0 + 21x + -21x + -7x2 + 7x2
-28 + -21x + 7x2 = 21x + -21x + -7x2 + 7x2

Combine like terms: 21x + -21x = 0
-28 + -21x + 7x2 = 0 + -7x2 + 7x2
-28 + -21x + 7x2 = -7x2 + 7x2

Combine like terms: -7x2 + 7x2 = 0
-28 + -21x + 7x2 = 0

Factor out the Greatest Common Factor (GCF), '7'.
7(-4 + -3x + x2) = 0

Factor a trinomial.
7((-1 + -1x)(4 + -1x)) = 0

Ignore the factor 7.

Subproblem 1

Set the factor '(-1 + -1x)' equal to zero and attempt to solve: Simplifying -1 + -1x = 0 Solving -1 + -1x = 0 Move all terms containing x to the left, all other terms to the right. Add '1' to each side of the equation. -1 + 1 + -1x = 0 + 1 Combine like terms: -1 + 1 = 0 0 + -1x = 0 + 1 -1x = 0 + 1 Combine like terms: 0 + 1 = 1 -1x = 1 Divide each side by '-1'. x = -1 Simplifying x = -1

Subproblem 2

Set the factor '(4 + -1x)' equal to zero and attempt to solve: Simplifying 4 + -1x = 0 Solving 4 + -1x = 0 Move all terms containing x to the left, all other terms to the right. Add '-4' to each side of the equation. 4 + -4 + -1x = 0 + -4 Combine like terms: 4 + -4 = 0 0 + -1x = 0 + -4 -1x = 0 + -4 Combine like terms: 0 + -4 = -4 -1x = -4 Divide each side by '-1'. x = 4 Simplifying x = 4

Solution

x = {-1, 4}

See similar equations:

| 4*(x-5)(x-5)+12=0 | | 3(3x-7)=2x+7 | | 2t-15=15 | | 5Y+2y=10 | | -44-16=12a | | 2t-15=13 | | 3(8x-15)=-2(3x+40) | | 3(2d+7)=9 | | x/1/5/1/3=23 | | -3(x+7)-42=2-50 | | b^2+2b-35=0 | | 8x+10=x^2-38 | | 3(x*5)=135/3 | | n/2-9=5+4n | | -7(x+3)-10=23+2 | | -3+-14= | | 3y+-y= | | -4(3-2z)=9z | | -12n=60 | | N/-8=7 | | =(1-2i)(1+2i) | | x/3+y=18 | | 13(7z^2)= | | -2x*x^2=0 | | 45+1x=128-2x | | 3x=2-(-10) | | 6z=14-38 | | -3+4=S | | -16-2x=4-8x | | 8x+10y=-12 | | Y=8^(-5/3)*(-3/5) | | 8-4(n)=4-6(n) |

Equations solver categories