The cost of a long distant telephone call is $0.36 for first minutes and $0.21 each additional minutes or portion thereof. Write an inequality representing the number of minutes a person could talk with out exceeding $3.00
would this be written as
0.36+0.21(x-1)<$3.00
0.36+(0.21(x)+0.21(-1))<3.00
0.36+(0.21x-0.21)<3.00
0.21x+0.15<3.00
0.21x<-0.15+3.00
0.21x<2.85
0.21x/0.21<2.85/0.21
x<2.85/0.21
x<2.85/0.21
x<13.57
to check i did this
0.36+0.21(13.57-1)<3.00
0.36+0.21(12.57)<3.00
0.36+2.639<3.00
0.36+2.64<3.00
3.00=3.00
aim i correct on this if i am not please tell me where i need look at to fix this
Your math is correct but the answer has to be 13 minutes, since the extra 0.57 minutes, or even 0.01 minute, would be billed as a full minute, making the bill 3.01
Your math is correct, but there is a small mistake in the interpretation. Since any additional minutes or portion thereof are billed as a full minute, you need to round up to the next whole number. So instead of 13.57 minutes, the correct answer is 14 minutes.
To fix the inequality, you can write it as:
0.36 + 0.21(x-1) ≤ 3.00
Then solve for x:
0.21x - 0.21 ≤ 3.00 - 0.36
0.21x ≤ 2.64
x ≤ 2.64 / 0.21
x ≤ 12.57
Therefore, a person could talk for up to 12 minutes and 57 seconds without exceeding $3.00. However, since the billing is done in full minutes, the answer should be rounded up to the next whole number, which is 13 minutes. So the correct answer is that a person could talk for up to 13 minutes without exceeding $3.00.