Question

(a+5)2= esse cinco e elevado a dois

Answer 1

Dada a propriedade do quadrado da soma:

$\mathsf{\left(a+b\right)^2=a^2+2ab+b^2}$

Logo:

$\mathsf{\left(a+5\right)^2=a^2+\left(2\cdot a\cdot 5\right)+5^2}\\\\\mathsf{\left(a+5\right)^2=a^2+10a+5^2}\\\\\boxed{\mathsf{\left(a+5\right)^2=a^2+10a+25}}\: \: \checkmark$