X - the rate charged by the first mechanic
y - the rate charged by the second mechanic
The sum of the two rates was $155.

The first mechanic worked for 10 hours, the second mechanic worked for 5 hours, and together they charged $1000.

Set 155-x and 200-2x equal to each other:

The rate charged by the first mechanic was $45, and the rate charged by the second mechanic was $110.
68
Schools almost over, good luck!!
So hmmm 7, 0, -7.... what the dickens is going on? hmmm is really dropping each time by 7, so, 7-7, 0, and 0-7, -7 and so on.
so, the "common difference" is then -7, and our first term is 7, now, who's -175? let's check.
1 - 2/3 = 1/3
1+ (-1/3) = 2/3