Solve (1,2-4/5)^-2+sqrt{25/16}-2^-1=

$$( 1,2 - \frac { 4 } { 5 } ) ^ { - 2 } + \sqrt { \frac { 25 } { 16 } } - 2 ^ { - 1 } =$$

Evaluate

$$7$$

Solution Steps

Subtract \frac{4}{5} from 1,2 to get \frac{2}{5}.

$$\left(\frac{2}{5}\right)^{-2}+\sqrt{\frac{25}{16}}-2^{-1}$$

Calculate \frac{2}{5} to the power of -2 and get \frac{25}{4}.

$$\frac{25}{4}+\sqrt{\frac{25}{16}}-2^{-1}$$

Rewrite the square root of the division \frac{25}{16} as the division of square roots \frac{\sqrt{25}}{\sqrt{16}}. Take the square root of both numerator and denominator.

$$\frac{25}{4}+\frac{5}{4}-2^{-1}$$

Add \frac{25}{4} and \frac{5}{4} to get \frac{15}{2}.

$$\frac{15}{2}-2^{-1}$$

Calculate 2 to the power of -1 and get \frac{1}{2}.

$$\frac{15}{2}-\frac{1}{2}$$

Subtract \frac{1}{2} from \frac{15}{2} to get 7.

$$7$$

Factor

$$7$$