Given a+b=7 and a–b=3, find: 3a÷3b

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

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.