Solve 4(4m+5)^2-9

$$4 ( 4 m + 5 ) ^ { 2 } - 9$$

Evaluate

$$\left(8m+7\right)\left(8m+13\right)$$

Solution Steps

Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(4m+5\right)^{2}.

$$4\left(16m^{2}+40m+25\right)-9$$

Use the distributive property to multiply 4 by 16m^{2}+40m+25.

$$64m^{2}+160m+100-9$$

Subtract 9 from 100 to get 91.

$$64m^{2}+160m+91$$

Expand

$$64m^{2}+160m+91$$

Solution Steps

Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(4m+5\right)^{2}.

$$4\left(16m^{2}+40m+25\right)-9$$

Use the distributive property to multiply 4 by 16m^{2}+40m+25.

$$64m^{2}+160m+100-9$$

Subtract 9 from 100 to get 91.

$$64m^{2}+160m+91$$