Solve =800(320*200-80*200)^2/400*400*520*280

$$= \frac { 800 ( 320 \times 200 - 80 \times 200 ) ^ { 2 } } { 400 \times 400 \times 520 \times 280 }$$

Evaluate

$$\frac{7200}{91}\approx 79.120879121$$

Solution Steps

Cancel out 2\times 400 in both numerator and denominator.

$$\frac{\left(200\times 320-80\times 200\right)^{2}}{200\times 280\times 520}$$

Multiply 200 and 320 to get 64000.

$$\frac{\left(64000-80\times 200\right)^{2}}{200\times 280\times 520}$$

Multiply 80 and 200 to get 16000.

$$\frac{\left(64000-16000\right)^{2}}{200\times 280\times 520}$$

Subtract 16000 from 64000 to get 48000.

$$\frac{48000^{2}}{200\times 280\times 520}$$

Calculate 48000 to the power of 2 and get 2304000000.

$$\frac{2304000000}{200\times 280\times 520}$$

Multiply 200 and 280 to get 56000.

$$\frac{2304000000}{56000\times 520}$$

Multiply 56000 and 520 to get 29120000.

$$\frac{2304000000}{29120000}$$

Reduce the fraction \frac{2304000000}{29120000} to lowest terms by extracting and canceling out 320000.

$$\frac{7200}{91}$$

Factor

$$\frac{2 ^ {5} \cdot 3 ^ {2} \cdot 5 ^ {2}}{7 \cdot 13} = 79\frac{11}{91} = 79.12087912087912$$