Solve for x
x=\frac{2}{7}\approx 0.285714286
x=-\frac{2}{7}\approx -0.285714286
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49x^{2}-4=0
Calculate the square root of 16 and get 4.
\left(7x-2\right)\left(7x+2\right)=0
Consider 49x^{2}-4. Rewrite 49x^{2}-4 as \left(7x\right)^{2}-2^{2}. The difference of squares can be factored using the rule: a^{2}-b^{2}=\left(a-b\right)\left(a+b\right).
x=\frac{2}{7} x=-\frac{2}{7}
To find equation solutions, solve 7x-2=0 and 7x+2=0.
49x^{2}-4=0
Calculate the square root of 16 and get 4.
49x^{2}=4
Add 4 to both sides. Anything plus zero gives itself.
x^{2}=\frac{4}{49}
Divide both sides by 49.
x=\frac{2}{7} x=-\frac{2}{7}
Take the square root of both sides of the equation.
49x^{2}-4=0
Calculate the square root of 16 and get 4.
x=\frac{0±\sqrt{0^{2}-4\times 49\left(-4\right)}}{2\times 49}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 49 for a, 0 for b, and -4 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times 49\left(-4\right)}}{2\times 49}
Square 0.
x=\frac{0±\sqrt{-196\left(-4\right)}}{2\times 49}
Multiply -4 times 49.
x=\frac{0±\sqrt{784}}{2\times 49}
Multiply -196 times -4.
x=\frac{0±28}{2\times 49}
Take the square root of 784.
x=\frac{0±28}{98}
Multiply 2 times 49.
x=\frac{2}{7}
Now solve the equation x=\frac{0±28}{98} when ± is plus. Reduce the fraction \frac{28}{98} to lowest terms by extracting and canceling out 14.
x=-\frac{2}{7}
Now solve the equation x=\frac{0±28}{98} when ± is minus. Reduce the fraction \frac{-28}{98} to lowest terms by extracting and canceling out 14.
x=\frac{2}{7} x=-\frac{2}{7}
The equation is now solved.
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