Question

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)

Answer 1

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