Answer: 8.9 units (choice C)
Explanation:
We plug
into the distance formula to get the following

First move the terms to get
6m-m=13+2
Then collect the like terms and calculate the sum, 5m=15
Divide both sides by 5
And you get m=3
I am too lazy I'll explain so you find 688 minus 267 then you divide the difference by 6 and then u subtract the difference from 267x100 because that will be the total. Then u find the mean of the 94 numbers u get!
You don't need 3 equations to get a general solution. To do this use the equations x-3y-z=0 and -x+2y+0z= -3. Start out by letting z = t. Then solving those 2 equations simultaneously, your x's cancel out leaving you with -y-z=-3. But since z=t, then -y=-3+t or y=3-t. Now sub that in for y in the first equation, along with the fact that z=t to get x-3(3-t)-t = 0 and solve for x. x=9-2t. So a general solution for this would be (9-2t, 3-t, t)
Let's use x to represent the number of hours since we don't know that.
750+250x<u><</u><u />2500
Subtract 750 from both sides.
250x<u><</u><u />1750
Divide both sides by 250.
x<u><</u><u />7
The most hours that they can do is 7, or it can be less.