One number is four fifths of another. If the sum of the numbers is 18, what is the lesser number?

Question

this is a math problem i am having trouble with
i think i am doing it right but i keep getting the wrong answer

Answer 1

Let x be the larger number. Then, the other number must be
18 - x, since the nubmers have a sum of 18.

If one number is four fifths of the other number, then
18 - x = (4/5)x

Now try multiplying both sides by 5 to eliminate the fraction.

5(18) - 5x = 4x
90 = 9x
10 = x

Therefore, the larger number is 10.

Since we want to know the lesser number, we need to take four fifths of 10.
(4/5)*10 = 4 * 10 / 5
= 8

There ya go!

Answer 2

This is extremely simple 2 variable expression. I've detailed my reasoning below:

x,y : 2 numbers

4x/5 = y

x + y = 18

x + 4x/5 = 18

5x + 4x
------- = 18
5

9x = 18 * 5

x = 90/9 = 10

y = 4x/5

y = 4 * 10 / 5 = 8


The two numbers are 10 and 8 so the answer is 8

Answer 3

18 divided by 9 times four and times five means eight and ten.

Answer 4

8.

(soppose one number is x and another number is y.
Then as given,
x=4/5(y)
x=4*y/5...........................(1)
The sum of the numbers is 18.
x+y=18.........................(2)

From (1) and (2),
4*y/5+y=18
y(4/5 + 1 )= 18
y((4+5)/5)=18
y(9/5)=18
y=18*5/9=10
y=10
now , x+y=18
x+10=18
x=18-10=8
x=8)

Answer 5

x=4/5y
5x-4y=0
4x+4y=72
adding
9x=72
x=8
nos are 10 and 8

Answer 6

1 keg of beer.