Skip to main content
Solve for x
Tick mark Image
Graph

Similar Problems from Web Search

Share

\left(x+5\right)^{2}=\frac{16}{4}
Divide both sides by 4.
\left(x+5\right)^{2}=4
Divide 16 by 4 to get 4.
x^{2}+10x+25=4
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(x+5\right)^{2}.
x^{2}+10x+25-4=0
Subtract 4 from both sides.
x^{2}+10x+21=0
Subtract 4 from 25 to get 21.
a+b=10 ab=21
To solve the equation, factor x^{2}+10x+21 using formula x^{2}+\left(a+b\right)x+ab=\left(x+a\right)\left(x+b\right). To find a and b, set up a system to be solved.
1,21 3,7
Since ab is positive, a and b have the same sign. Since a+b is positive, a and b are both positive. List all such integer pairs that give product 21.
1+21=22 3+7=10
Calculate the sum for each pair.
a=3 b=7
The solution is the pair that gives sum 10.
\left(x+3\right)\left(x+7\right)
Rewrite factored expression \left(x+a\right)\left(x+b\right) using the obtained values.
x=-3 x=-7
To find equation solutions, solve x+3=0 and x+7=0.
\left(x+5\right)^{2}=\frac{16}{4}
Divide both sides by 4.
\left(x+5\right)^{2}=4
Divide 16 by 4 to get 4.
x^{2}+10x+25=4
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(x+5\right)^{2}.
x^{2}+10x+25-4=0
Subtract 4 from both sides.
x^{2}+10x+21=0
Subtract 4 from 25 to get 21.
a+b=10 ab=1\times 21=21
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as x^{2}+ax+bx+21. To find a and b, set up a system to be solved.
1,21 3,7
Since ab is positive, a and b have the same sign. Since a+b is positive, a and b are both positive. List all such integer pairs that give product 21.
1+21=22 3+7=10
Calculate the sum for each pair.
a=3 b=7
The solution is the pair that gives sum 10.
\left(x^{2}+3x\right)+\left(7x+21\right)
Rewrite x^{2}+10x+21 as \left(x^{2}+3x\right)+\left(7x+21\right).
x\left(x+3\right)+7\left(x+3\right)
Factor out x in the first and 7 in the second group.
\left(x+3\right)\left(x+7\right)
Factor out common term x+3 by using distributive property.
x=-3 x=-7
To find equation solutions, solve x+3=0 and x+7=0.
\left(x+5\right)^{2}=\frac{16}{4}
Divide both sides by 4.
\left(x+5\right)^{2}=4
Divide 16 by 4 to get 4.
x^{2}+10x+25=4
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(x+5\right)^{2}.
x^{2}+10x+25-4=0
Subtract 4 from both sides.
x^{2}+10x+21=0
Subtract 4 from 25 to get 21.
x=\frac{-10±\sqrt{10^{2}-4\times 21}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 10 for b, and 21 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-10±\sqrt{100-4\times 21}}{2}
Square 10.
x=\frac{-10±\sqrt{100-84}}{2}
Multiply -4 times 21.
x=\frac{-10±\sqrt{16}}{2}
Add 100 to -84.
x=\frac{-10±4}{2}
Take the square root of 16.
x=-\frac{6}{2}
Now solve the equation x=\frac{-10±4}{2} when ± is plus. Add -10 to 4.
x=-3
Divide -6 by 2.
x=-\frac{14}{2}
Now solve the equation x=\frac{-10±4}{2} when ± is minus. Subtract 4 from -10.
x=-7
Divide -14 by 2.
x=-3 x=-7
The equation is now solved.
\left(x+5\right)^{2}=\frac{16}{4}
Divide both sides by 4.
\left(x+5\right)^{2}=4
Divide 16 by 4 to get 4.
\sqrt{\left(x+5\right)^{2}}=\sqrt{4}
Take the square root of both sides of the equation.
x+5=2 x+5=-2
Simplify.
x=-3 x=-7
Subtract 5 from both sides of the equation.