Solve 400x^2-(8y+5)^2=

$$400 x ^ { 2 } - ( 8 y + 5 ) ^ { 2 } =$$

Evaluate

$$-\left(8y+5\right)^{2}+400x^{2}$$

Solution Steps

Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(8y+5\right)^{2}.

$$400x^{2}-\left(64y^{2}+80y+25\right)$$

To find the opposite of 64y^{2}+80y+25, find the opposite of each term.

$$400x^{2}-64y^{2}-80y-25$$

Expand

$$400x^{2}-64y^{2}-80y-25$$

Solution Steps

Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(8y+5\right)^{2}.

$$400x^{2}-\left(64y^{2}+80y+25\right)$$

To find the opposite of 64y^{2}+80y+25, find the opposite of each term.

$$400x^{2}-64y^{2}-80y-25$$