Question 1039493
x+y =35  where x is the number of hours the first mechanic worked. y is the number of hours the second mechanic worked
65x+45y = 1975

x+y =35 therefore y = 35-x

We replace y in equation 65x+45y = 1975 with 35-x


65x+45(35-x)= 1975 from here we get x = 20.
If x is 20 then y has to be 15 since both worked total of 35 hours.