Which statement shows the associative property of addition?
a.
if m + 3 = 18, then 18 = m + 3
b.
(u + 7) + 13 = u + (7 + 13)
c.
21 + 2y = 2y + 21
d.
3 · (5 · x) = (3 · 5) · x

correct answer is infinitely many solutions

step-by-step explanation:

2(2x + 3) = -4 + 2(2x + 5)

solving the above equation:

4x + 6 = -4 +4x +10

combining like terms

4x -4x = -4+10-6

0=0

since both sides are 0=0, we end up into true statement it means it has infinite many solutions.

so correct answer is infinitely many solutions

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.

3

step-by-step explanation:

because where the point where the 2 lines intersect is (3,-1) the x value is 3