PLEASE ANSWER THIS ASAP, I WILL BE GIVING YOU A THANKS! ..

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Step-by-step explanation:

7 - z = 3 + z + 4 - 2z

7 - 3 - 4 = z - 2z + z

0 = 0 (Infinitely many solutions)

5(a + 4) - 15 = -5(a - 1)

5a + 20 - 15 = -5a + 5

5a + 5a = 5 - 20 + 15

10a = 40

10a/10 = 40

a = 4

(one solution)

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

2d - 4 = 5 + 3d - 9

2d - 3d = 5 - 9 + 4

- d = 0

d = 0

(one solution)

-11(n - 2) + 8(n + 1) = -3(n + 10)

-11n + 22 + 8n + 8 = -3n - 30

-11n + 8n + 3n = -30 - 22 - 8

0 = -60

(no solutions)