Question

WHAT IS THE VALUE OF A IN 3A + B = 54 BUT WE B=9

Answer 1

3A + 9 = 54
Subtract 9 from both sides
3A = 45
Divide both sides by 3
A = 15

Answer 2

Answer: $A=15$

Step-by-step explanation:

  You have the following equation:

$3A + B = 54$

 In order to find the the value of the variable "A" when $B=9$, you need to substitute this value of "B" into the equation and then you must solve for  "A".

Applying this procedure, you get:

$3A + B = 54\\\\ 3A + 9 = 54\\\\3A=54-9\\\\3A=45\\\\A=\frac{45}{3}\\\\A=15$