C because you got to find the like term term
30 minutes on the first machine. 10 minutes on the second
4×2/8
5×2/10
6×2/12
7×2/14
8×2/16
9×2/18
10×2/20
There are a lot more problems but here are a couple to help you for now.
Answer:
x=-5/8, y=15/2, z=-10. (-5/8, 15/2, -10).
Step-by-step explanation:
4x-7y=5
8x+3z=-35
6y+3z=15
----------------
4x=7y+5
2(4x)=2(7y+5)
8x=14y+10
14y+10+3z=-35
14y+3z=-35-10
14y+3z=-45
-----------------------
14y+3z=-45
6y+3z=15
------------------
14y+3z=-45
-(6y+3z)=-15
---------------------
14y+3z=-45
-6y-3z=-15
--------------------
8y=-60
simplify,
y=15/2
6(15/2)+3z=15
45+3z=15
3z=15-45
3z=-30
z=-30/3
z=-10
8x+3(-10)=-35
8x-30=-35
8x=-35+30
8x=-5
x=-5/8
x=-5/8, y=15/2, z=-10.