Question

Find the solution to the following system by substitution.

y = x + 3
y = 3x + 1

A.
(0, 1)

B.
(–1, 2)

C.
(2, 5)

D.
(1, 4)

Answer 1

D. (1, 4)

Explanation:

y = x + 3

y = 3x + 1

Substitute x+3 in for y in the second equation.

x + 3 = 3x + 1

Now solve for x.

x-3x+3=1

-2x=1-3

-2x=-2

x=1

Now to find y, just put 1 in for x.

y=1+3

y=4

So x = 1, and y = 4, which can be written as (1, 4)