Question

What is the solution to the system of equations?

Use the substitution method.

y=−3x+1

2x+5y=18

Enter your answer in the boxes.

Answer 1

(-1, 4)

Explanation:

What you do is it tells you to use the substitution method so you take the first equation and substitute it into the y in the second equation.

2x+5(-3x+1)=18

2x-15x+5=18

-13x+5=18

-13x=13

x=-1.

You will then take the -1 and put it into the x in the first equation to get y.

y=-3(-1)+1.

y=3+1

y=4.

(-1, 4) is your answer.

Answer 2

(-1, 4)

Explanation:

It is convenient to use the expression for y that the first equation gives. Put that in the second equation.

2x +5(-3x+1) = 18

2x -15x +5 = 18 . . . . eliminate parentheses

-13x = 13 . . . . . . . . . . collect terms, subtract 5

x = -1 . . . . . . . . . . . . . divide by -13

Now, we can use this value of x in the first equation to find y.

y = -3(-1) +1 = 4

The solution is (x, y) = (-1, 4).