Inequalities
Chua pays a monthly fee of $25 for his phone service, plus $0.05 per minute of use.
Let M = number of minutes Chua uses the phone service.
His monthly cost for the phone service is:
C = 25 + 0.05M
The least he has been charged in a month is $89.40. If we want to know the number of minutes he used the service in that month, then we must solve the inequality:
25 + 0.05M ≥ 89.40
Subtracting 25:
0.05M ≥ 89.40 - 25
Operating:
0.05M ≥ 64.40
Dividing by 0.05:
M ≥ 64.40 / 0.05
M ≥ 1288
He has used his phone service at least for 1288 minutes in a month
342.21 rounded to the nearest tenth is 342.2. 49.29 rounded is 49.3. So 342.2 - 49.3 = 292.9
You can do this by cross multiplying
I’m pretty sure the answer is (y=sin(3x))
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You can use desmos for these kinds of questions(desmos is a graphing app)
