Question

Solve the following system of equations:

-2x + y = 1
-4x + y = -1

(3, 1)

(-1, 3)

(-1, -3)

(1, 3)

Answer 1

Please Help!

I will fan and medal!

Answer 2

Use elimination by subtracting the second equation from the first. Watch your signs!

Answer 3

Would it be D? @NoelGreco

Answer 4

Hello? @NoelGreco

Answer 5

-2x + y = 1 (equation 1)
-4x + y = -1 (equation 2)

for equation 1

-2x + y = 1
y = 1 + 2x (equation 3)

substitute this equation 3 to equation 2, then

-4x + y = -1
-4x + (1 + 2x) = -1
-4x + 1 + 2x = -1
-2x + 1 = -1
-2x = -1 - 1
-2x = -2
x = 2/2
x=1

Answer 6

then for y

y = 1 + 2x
y = 1 + 2(1)
y = 1 + 2
y = 3

Answer 7

So the answer is (x,y) = (1,3)

Answer 8

It'd D!!!!

Answer 9

Thank you so much! @gerryliyana