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