Set up a system of equations:
2x+3y=6
x-3y=9
You can solve this with elimination by adding the two equations together:
3x+0y = 15
3x=15
x=5
Then, plug this value back into either of the original equations to find the y value:
5-3y=9
-3y=4
y= -4/3
The point of intersection is (5,-4/3)
Well if you are looking for the profit margin we need how much is was when she bought it, because it doesn't say, you can't say It's a increase or a decrease, so you could say this is a investment.
But considering you put this under mathematics I assume there is more to this question you forgot to post.
Answer: (-2,2), (-8,-1)
Step-by-step explanation:
9/100 = x/90
Cross multiply to get 810 = 100x
Divide both sides by 100 to get x = 81 inches
Answer:
The amount of calories Lucie will burn by jumping for 1 minute is 8 calories
Step-by-step explanation:
The given data values are;
Minutes 
Calories Burned
40 320
80 640
120 960
160 1280
The value of calories burnt and the number of minutes of jump robe are seen to be directly proportional, such that we have;
40 minutes of jump rope will yield 320 calories burnt
Therefore we have;
1 minute of jump rope will yield 320/40 = 8 calories burnt
The amount of calories Lucie will burn by jumping for 1 minute = 8 calories.
