18
First you want to change the 20% into a decimal which is .20
Next you want to multiply 90 by .20 because that will give you the answer for 20% of 90
90x.20=18
Hope that helps
The amount he had to pay if he have to purchase a laptop today that is the same value as the one he saw in the ad is $ 390.24.
Given that:-
Price of the laptop after 1 year = $ 400.
Inflation rate = 2.5 %
We have to find the amount he had to pay if he have to purchase a laptop today that is the same value as the one he saw in the ad.
Let the price he had to pay be x.
Hence, we can write,
x + (x*(2.5)*1)/100 = 400
x(1 + 1/40) = 400
x(41/40) = 400
x = 400*40/41 = $ 16000/41 = $ 390.24.
To learn more about amount, here:-
brainly.com/question/8082054
#SPJ1
Answer:
Step-by-step explanation:
9a - 8 = 2a - 2b
7a - 8 = -2b
7a = 8 - 2b
a = (8 - 2b)/7