Question

Use the substitution method to solve this system.
y = 2x+4
3x+y = 9

Answer 1

Answer:

x = 1, y = 6

Point: (1, 6)

Explanation:

y = 2x + 4

3x + y = 9

Since it’s saying that y = 2x + 4, substitute y for y = 2x + 4 in the second equation.

3x + 2x + 4 = 9

Add 3x + 2x (combining like terms)

5x + 4 = 9

Subtract 4 from 9

5x = 5

Solve for x

x = 1

Use x in the first equation.

y = 2x + 4

y = 2(1) + 4

y = 2 + 4

y = 6

Therefore x = 1 and y = 6
•••••••••••••••••••••••••••••••••••••••••••••••••
Check if the work is correct!

y = 6

x = 1

6 = 2(1) + 4

6 = 2 + 4

6 = 6


3(1) + (6) = 9

3 + 6 = 9

9 = 9

Answer 2

x = 1; y=6

Explanation:

y = 2x +4

3x + y = 9

Substitute 2x+4 for y in 3x+y = 9

3x + y = 9

3x + 2x+4 = 9

5x + 4 = 9

5x = 9-4

5x = 5

5x/5 = 5/5

x = 1

Substitute 1 for x in y = 2x +4

2(1) + 4

2 + 4

= 6

Answered by Gauthmath