Solve for x
x=1
Graph
Share
Copied to clipboard
8x^{3}+12x^{2}+6x+1-4x^{2}\left(2x+3\right)-7=0
Use binomial theorem \left(a+b\right)^{3}=a^{3}+3a^{2}b+3ab^{2}+b^{3} to expand \left(2x+1\right)^{3}.
8x^{3}+12x^{2}+6x+1-4x^{2}\left(2x+3\right)=7
Add 7 to both sides. Anything plus zero gives itself.
8x^{3}+12x^{2}+6x+1-8x^{3}-12x^{2}=7
Use the distributive property to multiply -4x^{2} by 2x+3.
12x^{2}+6x+1-12x^{2}=7
Combine 8x^{3} and -8x^{3} to get 0.
6x+1=7
Combine 12x^{2} and -12x^{2} to get 0.
6x=7-1
Subtract 1 from both sides.
6x=6
Subtract 1 from 7 to get 6.
x=\frac{6}{6}
Divide both sides by 6.
x=1
Divide 6 by 6 to get 1.
Examples
Quadratic equation
{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
Matrix
\left[ \begin{array} { l l } { 2 } & { 3 } \\ { 5 } & { 4 } \end{array} \right] \left[ \begin{array} { l l l } { 2 } & { 0 } & { 3 } \\ { -1 } & { 1 } & { 5 } \end{array} \right]
Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}