Question

helppppp pls simple algebra hella points show your work

Answer 1

Answer:

y = -7,   y = -3

Step-by-step explanation:

(y - 3)² = 2y² + 4y + 30

expand:

y² - 6y + 9 = 2y² + 4y + 30

subtract 30 from both sides

y² - 6y + 9 - 30= 2y² + 4y + 30 - 30

simplify:

y² - 6y - 21 = 2y² + 4y

subtract 4y from both sides

y² - 6y - 21 -4y = 2y² + 4y - 4y

simplify:

y² - 10y - 21 = 2y²

subtract 2y² from both sides

y² - 10y - 21 - 2y² = 2y² - 2y²

simplify:

-y² - 10y - 21 = 0

solve y by quadratic equation

         - (-10) ± √ (-10² - 4(-1)(21)

y = --------------------------------------

               2(-1)

y = -7,   y = -3

Answer 2

Answer:

$\Huge \boxed{y=-7 \ \ \mathrm{or} \ \ y=-3}$

$\rule[225]{225}{2}$

Step-by-step explanation:

$(y-3)^2 =2y^2 +4y+30$

Expanding brackets.

$y^2-6y+9=2y^2 +4y+30$

Subtracting (y² - 6y + 9) from both sides, then switching sides.

$y^2 +10y+21=0$

Factoring left side.

$(y+3)(y+7)=0$

Setting factors equal to 0.

$\Longrightarrow y+3= 0 \\\\\\ \Longrightarrow y=-3$

$\Longrightarrow y+7=0 \\\\\\ \Longrightarrow y=-7$

$\rule[225]{225}{2}$