The cost for a long-distance telephone call is $0.36 for the
first minute and $0.21 for each additional minute or portion thereof. Write an
inequality representing the number of minutes a person could talk without
exceeding $3.
2007-05-30 15:48:46 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
x = total number of minutes
.36 + .21*(x - 1) <= 3.00
2007-05-30 15:52:00 · answer #1 · answered by cscokid77 3 · 0⤊ 0⤋
Let x be the number of minutes a person can talk without exceeding $3.
Forming an inequality...
0.36 + 0.21(x-1) < 3
Multiplying 100 throughout the inequality...
36 + 21(x-1) < 300
Expanding the inequality...
36 + 21x -21 < 300
Simplifying the inequality...
15 + 21x < 300
21x < 285
x < 13.57 (to 4 significant figures)
Therefore, the inequality is 0.36 + 0.21(x-1) < 3 and the number of minutes a person could talk without exceeding $3 is 13.57.
2007-05-30 23:02:52 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Let x be no. of minutes person can talk.
0.36 + 0.21(x - 1) ⤠3
0.21x - 0.21 ⤠3 - 0.36
0.21x ⤠3 - 0.36 + 0.21
0.21x ⤠2.85
x ⤠13.6
Person could talk for 13 mins (rounded down)
2007-05-31 02:53:59 · answer #3 · answered by Como 7 · 0⤊ 0⤋
0.36 + 0.21x is less than or equal to 3
Subtract 0.36 from both sides.
0.21x is less than or equal to 2.64
x is less than or equal to 12.57
Therefore, you can't talk longer than 12 minutes.
12 minutes would cost $2.88
13 minutes would cost $3.09
2007-05-30 22:54:50 · answer #4 · answered by ExtraordinarY 2 · 0⤊ 0⤋
.21(m-1)=.36 is less than or equal to 3
2007-05-30 22:51:59 · answer #5 · answered by savage708 3 · 0⤊ 1⤋
Voice over IP = +$ in your Pocket
2007-05-30 22:52:36 · answer #6 · answered by Anonymous · 0⤊ 0⤋