Question

B=3/4a

a+b=21

A. a=30 b=15
B.a=371/4 b=-161/4
C. a=20 b=11
D. a=12 b=9

Answer 1

D option

Explanation:

a + b = 21

Placing value of b as 3/4a,

a + 3/4a = 21

7a/4 = 21

a = 12

Putting value of a in b=3/4a,

b = 3 × 12/4 = 9

a = 12, b = 9

Hope it helps.