Which ordered pair in the form (a, b) is a solution of this equation?

3a - 4b = 21

A.

(-2, - 3)

B.

(0, 7)

C.

(-3, - 2)

D.

(7, 0)

3a - 4b = 21

check (-2, - 3)

3 (-2) - 4 (-3) = 21

-6 + 12 = 21

6 does not = 21 so NO

check (0, 7)

3 (0) - 4 (7) = 21

0-28=21

-28 does not equal 21 so NO

check (-3, - 2)

3 (-3) - 4 (-2) = 21

-9 + 8 = 21

1 does not = 21 so NO

check (7, 0)

3 (7) - 4 (0) = 21

21 = 21

Choice D