Question 966644
One week she worked 17 hours on the day shift and 8 hours on the night shift and earned $191.
 the following week, she earned $219 for working 12 day shift hours and 15 night shift hours.
 what is her hourly rate for each shift?
:
let d = day hourly wage
let n = night " "
:
Write an equation for each week
17d + 8n = 191
12d + 15n = 219
:
Rearrange the 2nd equation to use as substitution in the first equation
12d + 15n = 219
Simplify, divide by 3
4d + 5n = 73
4d = -5n + 73
d = {{{-5/4}}}n + {{{73/4}}}
d = -1.25n + 18.25
:
17d + 8n = 191
replace d with (-1.25n+18.25)
17(-1.25n+18.25) + 8n = 191
-21.25n + 310.25 + 8n = 191
-21.25n + 8n = 191 - 310.25
-13.25n = -119.25
n = -119.25\-13.25
n = $9.00 an hr at night
then
d = -1.25(9) + 18.25
d = -11.25 + 18.25
d = $7.00 an hr in the daytime
:
:
See if that checks out in the original 2nd equation
12(7) + 15(9) = 219
84 + 135 = 219