Question

What is the value of a in the equation 3a+b=54 when b=9

Answer 1

3a + b = 54...when b = 9
3a + 9 = 54
3a = 54 - 9
3a = 45
a = 45/3
a = 15 <===

Answer 2

Salutations!

$3a+b = 54$

Replace b as 9

$3a+9=54$

$3a=54-9$

$3a=45$

$a= 45/3$

$a=15$

Thus, your answer is $15$

Hope I helped (:

Have a great day!