Question

Lashonda purchased a prepaid phone for $20 . Long distance calls cost 21 cents a minute using this card .lashonda used her card only once to make a long distance call . If the remaining credit on her card is $9.92 , how many minutes did her call last ?

Answer 1

So, if a long distance call costs 21 cents we just use a formula first we do 20 - 9.92, which gives us 10.08, then we divide it like this: 10.08 / 0.21, which gives 48! So, Lashonda spent 48 minutes making a long distance call! Hope this helped! Brainliest is always appreciated.

Answer 2

For this case, the first thing we must do is define a variable.
 We have then:
 x: number of minutes
 y: total cost of the call.
 We now write the equation that models the problem:
 $y = -0.21x + 20$
 Since the remaining credit is 9.92 $, then we evaluate the value of y = 9.92 in the equation:
 $9.92 = -0.21x + 20$
 From here, we clear the value of x:
 $0.21x = 20 - 9.92 x = (20 - 9.92) / (0.21) X = 48 min$
 Answer:
 The last call was 48 minutes.