66.3k views
3 votes
Given a+b=7 and a–b=3, find: 3a÷3b

User Smilyface
by
8.7k points

1 Answer

4 votes

Answer & Step-by-step explanation:

We are given two equations...

a + b = 7

a - b = 3

We are asked to find 3a ÷ 3b. In order to find the value of a and b, we have to rearrange one of the equations so it will be easier to find the values of the variables. Let's rearrange the second equation.

a - b = 3 → a = 3 + b

Now that we have an equation that shows the value of a, we can use this equation and plug it into the first equation.

a + b = 7

a = 3 + b

(3 + b) + b = 7

3 + 2b = 7

2b = 4

b = 2

We have the value of b. Now, we have to find the value of a by plugging b into the second equation.

a - b = 3

b = 2

a - 2 = 3

a = 5

Now that we have the values of both variables, we can plug them into (3a÷3b)

3a ÷ 3b

3(5) ÷ 3(2)

15 ÷ 6

5/2 or 2.5

So, 3a ÷ 3b equals 5/2 or 2.5

User Chad Little
by
8.7k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories