-4x^2+8x+21=0

Simple and best practice solution for -4x^2+8x+21=0 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 -4x^2+8x+21=0 equation:


Simplifying
-4x2 + 8x + 21 = 0

Reorder the terms:
21 + 8x + -4x2 = 0

Solving
21 + 8x + -4x2 = 0

Solving for variable 'x'.

Factor a trinomial.
(7 + -2x)(3 + 2x) = 0

Subproblem 1

Set the factor '(7 + -2x)' equal to zero and attempt to solve: Simplifying 7 + -2x = 0 Solving 7 + -2x = 0 Move all terms containing x to the left, all other terms to the right. Add '-7' to each side of the equation. 7 + -7 + -2x = 0 + -7 Combine like terms: 7 + -7 = 0 0 + -2x = 0 + -7 -2x = 0 + -7 Combine like terms: 0 + -7 = -7 -2x = -7 Divide each side by '-2'. x = 3.5 Simplifying x = 3.5

Subproblem 2

Set the factor '(3 + 2x)' equal to zero and attempt to solve: Simplifying 3 + 2x = 0 Solving 3 + 2x = 0 Move all terms containing x to the left, all other terms to the right. Add '-3' to each side of the equation. 3 + -3 + 2x = 0 + -3 Combine like terms: 3 + -3 = 0 0 + 2x = 0 + -3 2x = 0 + -3 Combine like terms: 0 + -3 = -3 2x = -3 Divide each side by '2'. x = -1.5 Simplifying x = -1.5

Solution

x = {3.5, -1.5}

See similar equations:

| CosB=0.5000 | | S/9-5=4 | | 16g-12g=-20 | | 5 = 40s | | CosY=0.5736 | | -10y-4=5+4y | | y-3=8/7(x-2) | | 3m+2m=5 | | -29=8x-5 | | 49s^2-56s+16=0 | | SinA=0.4540 | | -3(5p+3)-2(6-17)=3(9+6p) | | (4m+6)+(5n+9)= | | y-5/2y=y-4/3 | | 4x+6y+2x-y= | | 5x-10=1x+20 | | 3x-5x-7=-2x+6-7 | | 1=2h-10-7 | | -12+22= | | 18b-21=15b+13 | | 18m-12=60 | | 3y^2=15y^2 | | 12x^2+55x+52=0 | | -6y-4y=-3 | | (2,-1);y=3/2(x-2) | | 3(5x-6)-2=x-(17-x) | | 2v+10=48 | | 7x/8=16 | | 12p-8p-3p+3=20 | | (2x)+(1.5x)=75 | | lnx-0.5lny=0 | | ln(5)/.6 |

Equations solver categories