Tim's phone service charges $22.49 plus an additional $0.17 for each text message sent per month. If Tim's phone bill was $26.74, which equation could be used to find how many text messages, x, Tim sent last month?
A.
$0.17x + $22.49 = $26.74

B.
$22.49x + $0.17 = $26.74

C.
$0.17x - $22.49 = $26.74

D.
$22.49x - $0.17 = $26.74

Me. i can't figure out this question. give an explanation too. .

What is always true when two whole numbers are subtracted?

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.