Answer:
y=-5,x=2
Step-by-step explanation:
3x+3y=-9________________eqn 1
3x-3y=21________________eqn 2
using elimination method
3x+3y=-9
-
3x-3y=21
subtract equation 2 from equation 1
0+6y=-30
6y=-30
y=-30/6
y=-5
substitute the value of y in equation 1
3x+3y=-9
3x+3(-5)=-9
3x-15=-9
3x=-9+15
3x=6
x=6/3
x=2
9514 1404 393
Answer:
A. $0.85
Step-by-step explanation:
Each time m increases by 1, the cost goes up by $0.85.
The cost per mile is $0.85.
Put them into y=mx+b
y=1/3x -1
y=2/3x-4
Graph them. Where they touch is your answer. No touch? No solution. Same line? Infinite solutions.
Second set: Same thing.
Solution to first set is (9,2)