Two mechanics worked on a car. The first mechanic worked for 15 hours, and the second mechanic worked for 5 hours. Together theycharged a total of $1225. What was the rate charged per hour by each mechanic if the sum of the two rates was $135 per hour?

Respuesta :

Answer:

The mechanic who worked for 15 hours charged $55 per hour, while the mechanic that worked for 5 hours charged $80 per hour.

Given:

x = rate of the mechanic who worked 15 hours

y = rate of the mechanic who worked 5 hours

Since the total of their rates is $135, we cuold express it as

x + y = 135

Then, since they are charges a total of $1225 after working, we could express it as

15x + 5y = 1225

Now that we have two expressions:

x + y = 135.................Equation 1

15x + 5y = 1225........Equation 2

We can solve for one variable through substitution

[tex]x+y=135\rightarrow x=135-y[/tex]

*Substitute x to the second equation

[tex]15x+5y=1225[/tex][tex]15(135-y)+5y=1225[/tex]

*Solve for y

[tex]2025-15y+5y=1225[/tex][tex]-15y+5y=1225-2025[/tex][tex]-10y=-800[/tex]

*Divide both sides by -10

[tex]\frac{-10y}{-10}=\frac{-800}{-10}[/tex][tex]y=80[/tex]

Now we got a value for y, let us substitute this to the first equation to get the value of x.

[tex]x+y=135[/tex]

*Substitute y = 80

[tex]x+(80)=135[/tex][tex]x+80=135[/tex][tex]x=135-80[/tex][tex]x=55[/tex]

Now, we got a value for x which is 55.

Going back to our given, since:

x = rate of the mechanic who worked 15 hours

y = rate of the mechanic who worked 5 hours

The mechanic who worked for 15 hours charged $55 per hour, while the mechanic that worked for 5 hours charged $80 per hour.