Solve 100=quad-1/2(x)(.4)^2

$$100 = \quad - \frac { 1 } { 2 } ( x ) ( .4 ) ^ { 2 }$$

Solve for x

$$x=-1250$$

Steps for Solving Linear Equation

Calculate 0.4 to the power of 2 and get 0.16.

$$100=-\frac{1}{2}x\times 0.16$$

Convert decimal number 0.16 to fraction \frac{16}{100}. Reduce the fraction \frac{16}{100} to lowest terms by extracting and canceling out 4.

$$100=-\frac{1}{2}x\times \frac{4}{25}$$

Multiply -\frac{1}{2} times \frac{4}{25} by multiplying numerator times numerator and denominator times denominator.

$$100=\frac{-4}{2\times 25}x$$

Do the multiplications in the fraction \frac{-4}{2\times 25}.

$$100=\frac{-4}{50}x$$

Reduce the fraction \frac{-4}{50} to lowest terms by extracting and canceling out 2.

$$100=-\frac{2}{25}x$$

Swap sides so that all variable terms are on the left hand side.

$$-\frac{2}{25}x=100$$

Multiply both sides by -\frac{25}{2}, the reciprocal of -\frac{2}{25}.

$$x=100\left(-\frac{25}{2}\right)$$

Express 100\left(-\frac{25}{2}\right) as a single fraction.

$$x=\frac{100\left(-25\right)}{2}$$

Multiply 100 and -25 to get -2500.

$$x=\frac{-2500}{2}$$

Divide -2500 by 2 to get -1250.

$$x=-1250$$