How do you solve (2y + 5)^2 = 25?

2 Answers
May 25, 2018

y=0 or y=-5

Explanation:

writing
(2y+5)^2-5^2=0
(2y+5-5)(2y+5+5)=0
this gives
2y=0
or
2y+10=0
this gives
y=0 or y=-5

May 25, 2018

y=0,-5

Explanation:

Solve:

(2y+5)^2=25

Take the square root of both sides.

sqrt((2y+5)^2)=sqrt25

2y+5=+-5

This gives us two equations:

color(blue)(2y+5=+5 and color(green)(2y+5=-5

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

color(blue)(2y+5=5

Subtract 5 from both sides.

2y+5-5=+5-5

2y=0

Divide both sides by 2.

y=0/2

y=0

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

color(green)(2y+5=-5

Subtract 5 from both sides.

2y+5-5=-5-5

2y=-5-5

2y=-10

Divide both sides by 2.

y=-10/2

y=-5

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Solutions for y.

y=0,-5