Question

Solve the system.
y = 2 - x and y = 4x + 7
Answer

(1, 1)

(1, 3)

(-1, 3)

(-1, 1)

no solution

Answer 1

compare the equations and get the value for x
put that value of x in any of the two given equations ad get value for y and get your solution.

Answer 2

y = 2 - x
now sub 2 - x in for y in the other equation
y = 4x + 7
2 - x = 4x + 7
2 - 7 = 4x + x
-5 = 5x
-5/5 = x
-1 = x
now sub -1 in for x in either of the equations to find y
y = 2 - x
y = 2 - (-1)
y = 2 + 1
y = 3
now lets check it....
y = 4x + 7
3 = 4(-1) + 7
3 = -4 + 7
3 = 3 (correct)
ANSWER : x = -1 and y = 3 or (-1,3)