Question

What is the intermediate step in the form (x+a)^2=b as a result of completing the square for the following equation? Please help

Answer 1

Answer:

${( \bold {\purple{ \boxed{ x + 7}}})}^{2} = \: \bold {\purple{ \boxed{ 9}}}$

Step-by-step explanation:

$- 2 {x}^{2} - 28x = 80 \\ \\ - 2( {x}^{2} + 14x) = 80 \\ \\ {x}^{2} + 14x = - 40 \\ \\ {x}^{2} + 2.x. \bold{ \red{7 }}+ 49 = - 40 + 49 \\ (add \: square \: of \: 7 \: both \: sides)\\ \\ {x}^{2} + 14x + {7}^{2} = 9 \\ \\ {( \bold {\purple{ \boxed{ x + 7}}})}^{2} = \: \bold {\purple{ \boxed{ 9}}}$