Question

Hello,

I have some practice math I'm working through and I'm unsure about the answer. I will also put what I got. Thanks for the help.

1. Solve using any method and identify the system as consistent, inconsistent, or dependent.
-2x+y=8
2x+2y=-8

A.) (-4,0); consistent/independent
B.) (-4,0); consistent/dependent
C.) {(-4,0 | -2x+y=8} ; consistent/dependent
D.) zero with a line through it;consistent

I thought C for this one.


2.) Solve the system using the elimination method. If the system is inconsistent or dependent, so state.
x-2y+5z=1
-x-2y+3z=-5
2x-4y+10z=3

A) (5,-3,-2)
B) (5,-4,-1)
C) dependent
D) no solution, inconsistent

I got C for this one.

3.) Solve using any method and identify the system as consistent, inconsistent, or dependent.
0.2y=0.4x+0
0.8x-0.4y=5

A.) zero with a line through it; inconsistent
B) zero with a line through it; consistent
C) zero with a line through it; dependent
D) Determination is not possible with the given information

I got A for this.

Answer 1

1. Should be C (IF not, then B)
2. D, if you multiply 1st equation by 2, try subtracting the third equation, and you get 0 = 5 or 0 = -1
3.
2y = 4x
8x-4y=5
-4y = 5-8x
4y = 8x-5
2y = 4x - 5/2

When minus the first equation from this, we get 0 = -5/2

So, A.