Answer:
4x+20+2
4x+22
Step-by-step explanation:
4×x=4x then 4×5=20+2
We can build a system of two linear equations with two unknowns with the info provided in the problem, one with Kelsey info and one with Mitch info like so:
Lets call p the amount on peak minutes and n the amount of non-peak minutes:
45p + 50n = 27.75
70p + 30n = 36
lets reduce the equations dividing the first by 5:
9p + 10n = 5.55
<span>70p + 30n = 36
</span>now, to eliminate n, lets multiply the first equation by -3 and add the two equations:
-27p - 30n = -16.65
<span>70p + 30n = 36
</span>----------------------------
43p + 0 = 19.35
p = 19.35<span>/43
p = 0.45
therefore the peak rate is $0.45 per minute
lets substitute in one of the original equations this result:
</span><span>45p + 50n = 27.75
</span>45(0.45) + 50n = 27.75
20.25 <span>+ 50n = 27.75
50n = 27.75 - 20.25
50n = 7.5
n = 7.5/50
n = 0.15
therefore the non-peak rate per minute is $0.15</span>
Exact form: 7/12
decimal form: 0.583 (repeating sign over 3)
