Question

What is the answer to this problem
x + 2y = 3
3x - 2y = 5 using subsitoution

Answer 1

y = 1 ; x = 1 ; or (1, 1)

Explanation: Solve for x in the first equation and substitute it into the second equation and solve for y.

See photo for work

Answer 2

x=2

y=1/2

Explanation:

x + 2y = 3 Equation 1

3x - 2y = 5 Equation 2

From equation 1, we make x the subject

x + 2y = 3

x=3-2y Equation 3

We substitute x for 3-2y in equation 2 to get y

3x - 2y = 5

3(3-2y)-2y=5

9-6y-2y=5

9-8y=5

9-5=8y

4=8y

Divide both sides by 8

4/8=8y/8

4/8=y

y=1/2

Substitute y for 1/2 in equation 3

x=3-2y

x=3-2(1/2)

x=3-1

x=2

Let's use equation 2 to check if we are correct, note that both sides of the equation must be the same. We substitute x with 2 and y with 1/2

3x - 2y = 5

3(2)-2(1/2)=5

6-1=5

5=5