7x^2+7=21

Simple and best practice solution for 7x^2+7=21 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 7x^2+7=21 equation:


Simplifying
7x2 + 7 = 21

Reorder the terms:
7 + 7x2 = 21

Solving
7 + 7x2 = 21

Solving for variable 'x'.

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

Add '-7' to each side of the equation.
7 + -7 + 7x2 = 21 + -7

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

Combine like terms: 21 + -7 = 14
7x2 = 14

Divide each side by '7'.
x2 = 2

Simplifying
x2 = 2

Take the square root of each side:
x = {-1.414213562, 1.414213562}

See similar equations:

| 10n^2+9=49 | | 2x+y=435 | | 4x^2+10x+9=5 | | (273+(-1.7x))+26x=4100 | | 4b-2=38 | | n^2=-6+5n | | 130=13x-2 | | 146=6x+7 | | 26x+15Y=4100 | | 3x+4=3x-3 | | 12x+6=17x-26 | | 122=40x+2 | | 5(84-.6y)+3y=420 | | 12x+96=264 | | ln(x^2-5x-5)=0 | | 1x+5x=0 | | 4-7=37 | | sin(2x-pi/4)=0 | | 7x-3=3x-1 | | A==2b/c;c | | 3x^2-24x+50=149 | | X(x+3)(x+5)(x+8)+56=0 | | x^3(13x-3)=0 | | 60x^2-12xy/20x | | 8/9x1y=2/3 | | 8/9x1x=2/3 | | (a-44)*4=64 | | 8(6x-3)=22+2x | | Y=35t+420 | | -4(4-2x)+4=-12-5x | | 18=-7b+9b | | 15=-5c+10c |

Equations solver categories