Answer:
First mechanic worked 20 hours and second mechanic worked 5 hours
Step-by-step explanation:
Let the number of hours the first mechanic worked = [tex]a[/tex]
Let the number of hours the second mechanic worked = [tex]b[/tex]
Therefore, we can write 2 equations and then solve them simultaneously:
[tex]a+b=25[/tex]
[tex]65a+90b=1750[/tex]
Rearranging the first equation: [tex]a=25-b[/tex]
and substituting into the second equation to find [tex]b[/tex]:
[tex]65(25-b)+90b=1750[/tex]
[tex]1625-65b+90b=1750\\ 25b=125\\ b=5[/tex]
Now sub [tex]b=5[/tex] into the first equation to find [tex]a[/tex]
[tex]a+5=25\\ a=20[/tex]
Therefore, first mechanic (a) worked 20 hours and second mechanic (b) worked 5 hours