Answer:
a = 15
Step-by-step explanation:
Given
3a + b = 54 ← substitute b = 9
3a + 9 = 54 ( subtract 9 from both sides )
3a = 45 ( divide both sides by 3 )
3a+b=54, b=9
3a +9 =54
3a= 54-9=45
a= 45÷3=15
c
yes the anwer is A
i dont understand
