Answer is in the photo. I couldn't attach it here, but uploaded it to a file hosting. link below! Good Luck!
cutt.ly/XzW3SUN
First: $65
Second: $115
Step-by-step explanation:
We write equations for each part of this situation.
The Total Charge
Together they charged 1550. This means 1550 is made up of the first mechanics rate for 15 hours and the second's rate for 5 hours. Lets call the first's rate a, so he charges 15a. The second's let's call b. He charges 5b. We add them together 15a+5b=1550.
The Sum of the Rates
Since the first's rate is a and the second is b, we can write a+b=180 since their sum is 180.
We solve for a and b by substituting one equation into another. Solve for the variable. Then substitute the value into the equation to find the other variable.
For a+b=180, rearrange to b=180-a and substitute into 15a+5b=1550.
15a + 5 (180-a)=1550
15a+900-5a=1550
10a+900-900=1550-900
10a=650
a=$65 was charged by the first mechanic.
We substitute to find the second mechanic's rate.
65+b=180
65-65+b=180-65
b= $115 was charged by the second mechanic