## anonymous one year ago Two mechanics worked on a car. The first mechanic charged $75 per hour, and the second mechanic charged$110 per hour. The mechanics worked for a combined total of 20 hours, and together they charged a total of $2025. How long did each mechanic work? Will medal • This Question is Closed 1. jdoe0001 so.. let's say hmmm the hours the$75 mechanic worked was $$\bf x$$ and the hours the $110 mechanic worked was $$\bf y$$ how many hours did they work together? 2. anonymous 20 3. jdoe0001 so... they worked together 20 hours we dunno what those hours are, but we can call them "x" and "y" so we could say that $$\bf x+y=20$$ the mechanic that charges$75 per hour, after "x" hours, he ended up charging 75*x or 75x the mechanic that charges \$110 per hour, after "y" hours, he ended up charging 110*y or 110y now, their total bill was 2025 so we could also say that $$\bf 75x+110y = 2025$$ any ideas?

4. anonymous

im confused i have to give hours for mechanic one and mechanic 2

5. anonymous

i have 4 questions like this i really want to know how tp figure them out

6. jdoe0001

yes.... notice... x+y = 20 so... if you solve that for say "y"... how does it look like?

7. jdoe0001

the hours, notice above, for each is "x" and "y", thus

8. texaschic101

this is basically a substitution problem involving the 2 equations up above ^^. We have : x + y = 20 ----> x = -y + 20 75x + 110y = 2025 now sub -y + 20 in for x back into the second equation....you will then be solving for y, the hrs for the mechanic that charges 110 per hr.

9. anonymous

mechanic 1 5 hours mechanic 2 15 hours ??

10. texaschic101

lets check by subbing in your answers into the 2nd equation.. 75x + 110y = 2025 75(5) + 110(15) = 2025 375 + 1650 = 2025 2025 = 2025 (correct) yes...that is correct

11. anonymous

ty for explaining it

12. texaschic101

medal should go to jdoe....he/she helped you set it up...without that, you have nothing...lol

13. anonymous

you stayed to make sure i understood..

14. texaschic101

all is good...I gave jdoe a medal I am always happy to help when I can :)

15. anonymous

ty

16. texaschic101

:)