Use substitution to solve the system of equations given by y = 2x and 5x + y = 7. MULTIPLE CHOICE?

0 ⤊

(1, 2)
(2, 4)
(2, 3)
(2, -3)

2007-04-28 16:47:46 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics

y = 2x
5x + y = 7
Substitute
y = 2x into second equation
5x + 2x = 7
x = 1
So y = 2
Answer (1,2)

2007-04-28 16:51:26 · answer #1 · answered by looikk 4 · 0⤊ 0⤋

We replace y by 2x in the second equation. This gives us 7x=7 or x=1. Then y=2. The coordinate for this is (1,2)

2007-04-28 23:51:55 · answer #2 · answered by cattbarf 7 · 0⤊ 0⤋