Question

1. y = x + 6
y = 2x (1 point)
(6, 12)
(–12, –6)
(–6, –12)
(2, 4)
2. 3x + 2y = 7
–3x + 11 = y (1 point)
(6, –3)
(6, –7)

(5, –4)
3. 2x – y = –7
4x – y = –4
(–1.5, 4)
(1.5, 10)
(4, –1.5)
(–1.5, –2)
For questions 4–5, how many solutions does the system have?

4. –4y + 4 = x
2x + 8y = 8
one solution
two solutions
infinitely many solutions
no solution
5. 6x + 2 = y
3y – 18x = 12
one solution
two solutions
infinitely many solutions
no solution

Answer 1

For questions 1–3, what is the solution of the system? Use substitution.
For questions 4–5, how many solutions does the system have?

Answer 2

for 1-3, substitute y=2x into first equation.
2x=x+6
2x-x=6
x=6
substitute x=6 into 2nd equation
y=2x
y=2*6
=12
(6.12)