Solve for x
x = \frac{10}{7} = 1\frac{3}{7} \approx 1.428571429
x = -\frac{10}{7} = -1\frac{3}{7} \approx -1.428571429
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10=\frac{49}{10}x^{2}
Multiply \frac{1}{2} and 9.8 to get \frac{49}{10}.
\frac{49}{10}x^{2}=10
Swap sides so that all variable terms are on the left hand side.
\frac{49}{10}x^{2}-10=0
Subtract 10 from both sides.
49x^{2}-100=0
Multiply both sides by 10.
\left(7x-10\right)\left(7x+10\right)=0
Consider 49x^{2}-100. Rewrite 49x^{2}-100 as \left(7x\right)^{2}-10^{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{10}{7} x=-\frac{10}{7}
To find equation solutions, solve 7x-10=0 and 7x+10=0.
10=\frac{49}{10}x^{2}
Multiply \frac{1}{2} and 9.8 to get \frac{49}{10}.
\frac{49}{10}x^{2}=10
Swap sides so that all variable terms are on the left hand side.
x^{2}=10\times \frac{10}{49}
Multiply both sides by \frac{10}{49}, the reciprocal of \frac{49}{10}.
x^{2}=\frac{100}{49}
Multiply 10 and \frac{10}{49} to get \frac{100}{49}.
x=\frac{10}{7} x=-\frac{10}{7}
Take the square root of both sides of the equation.
10=\frac{49}{10}x^{2}
Multiply \frac{1}{2} and 9.8 to get \frac{49}{10}.
\frac{49}{10}x^{2}=10
Swap sides so that all variable terms are on the left hand side.
\frac{49}{10}x^{2}-10=0
Subtract 10 from both sides.
x=\frac{0±\sqrt{0^{2}-4\times \frac{49}{10}\left(-10\right)}}{2\times \frac{49}{10}}
This equation is in standard form: ax^{2}+bx+c=0. Substitute \frac{49}{10} for a, 0 for b, and -10 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times \frac{49}{10}\left(-10\right)}}{2\times \frac{49}{10}}
Square 0.
x=\frac{0±\sqrt{-\frac{98}{5}\left(-10\right)}}{2\times \frac{49}{10}}
Multiply -4 times \frac{49}{10}.
x=\frac{0±\sqrt{196}}{2\times \frac{49}{10}}
Multiply -\frac{98}{5} times -10.
x=\frac{0±14}{2\times \frac{49}{10}}
Take the square root of 196.
x=\frac{0±14}{\frac{49}{5}}
Multiply 2 times \frac{49}{10}.
x=\frac{10}{7}
Now solve the equation x=\frac{0±14}{\frac{49}{5}} when ± is plus. Divide 14 by \frac{49}{5} by multiplying 14 by the reciprocal of \frac{49}{5}.
x=-\frac{10}{7}
Now solve the equation x=\frac{0±14}{\frac{49}{5}} when ± is minus. Divide -14 by \frac{49}{5} by multiplying -14 by the reciprocal of \frac{49}{5}.
x=\frac{10}{7} x=-\frac{10}{7}
The equation is now solved.
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