Which equations are in standard form? check all that apply y = 2x + 5 2x + 3y = –6 –4x + 3y = 12 y = x – 9 x + 3 = 6 x – y = 5 5x + 3y =

The correct answers are:

2x + 3y = –6

and

x – y = 5

Given:
pool length : 10 yards
pool width : 8 yards

Area = 10 yds * 8 yds = 80 yd²

(10 + 2x)(8 + 2x) = 120 
10(8 + 2x) + 2x(8+2x) = 120
80 + 20x + 16x + 4x² = 120
4x² + 36x + 80 - 120 = 0
4x² + 36x - 40 = 0
4(x² + 9x - 10) = 0
4(x + 10)(x - 1) = 0

x + 10 = 0
x = -10
x - 1 = 0 
x = 1

the width of the deck is 1 yard