Answer:
2a is equal to 10.
Step-by-step explanation:
You can find out what a is by dividing both sides by the number that a's being multiplied by. So we need to divide both sides of the equation by 3:
3a = 15
3a ÷ 3 = 15 ÷ 3
a = 5
So we know that a is equal to five. 2a then, is just 2 × a:
2a
= 2 × a
= 2 × 5
= 10
