Question 7 (Essay Worth 5 points)
(08.03) Consider the following pair of equations:

y = 3x + 3
y = x − 1

Explain how you will solve the pair of equations by substitution. Show all the steps and write the solution in (x, y) form.

x = -2

y=-3

(-2,-3)

Step-by-step explanation:

Both equations are equal to y

We can set them equal to each other

y = 3x + 3

y = x − 1

3x+3 = x-1

Subtract x from each side

3x+3 -x = x-1-x

2x+3 = -1

Subtract 3 from each side

2x+3-3 = -1-3

2x = -4

Divide each side by 2

2x/2 = -4/2

x = -2

Now we need to find y

y = x-1

y = -2-1

y = -3

y = x-1

(-2,-3)

Step-by-step explanation:

y = 3x + 3

y = x − 1

Equate both the y's to get an equation in terms of x only. Making x the subject, solve for x. Substitute the value of x in any of the given equations to find y.

3x + 3 = x - 1

2x = -4

x = -2

y = -2 - 1 = -3

Solution is: (-2,-3)

5x+40

5(x + 8)

7x - 49

7(x - 7)

18x + 9

9(2x + 1)

15x - 10

5(3x - 2)

step-by-step explanation:

for number one all you have to do is factor 5 out of 5x + 40

for number 2 factor 7 out of 7x - 49

for number three factor 9 out of 18x + 9

for number four factor 5 out of 15x - 10