Step-by-step explanation:
b varies directly to c and square root of d
K is the constant
b=c
b=c/√d
b=Kc/√9
12= 8k/√9
12=8k/3
we crossed multiply
12*3=8k
36=8kb
we divide both sides by 8
K= 36/8
K= 18/4
K= 9/2
Go back to the equation
b=Kc/√d
b=9/2(11)/√25
b= 99/2/5
b= 49.5/5
b= 9.9 or b=10
