Question

solve the system by elimination
(system below)
a.(5,-1,0)
b.(-5,1,0)
c.(-5,-1,0)
d.(-5,-1,-2)

Answer 1

which letter do is easiest to eliminate 1st..?

Answer 2

x?

Answer 3

or the easier method is to use the points and substitute them into the equations

A(5, -1, 0)

so let x = 5, y = -1 and z = 0

5 + 5(-1) -4(0) = 0 you need -10 so answer A doesn't seem to work with equation 1

so try B

(-5, 1, 0)

-5 + 5(1) - 4(0) = 0 need -11

so eliminate B

C(-5, - 1, 0)

equation 1 -5 + 5(-1) - 4(0) = -10

so answer C seems to work with equation1...

try it on equation 2

2(-5) -(-1) + 5(0) = -9 so it seems to work on equation 2

test it with equation 3, if its correct, then you have the solution.

hope it helps

Answer 4

hope you don't need to show working, as this is a valid method for the information given.

Answer 5

This is perfect, thank you!!!