Question

The sum of two number is 18. 5 times the first number subtracted from 4/7bof the second number is 14. Find the number

Answer 1

Required numbers are x = -0.5 and y =18.6

Explanation:

Let the two numbers be x and y

Their sum is 18 i.e x+y= 18

4/7y-5x= 14

We need to find the numbers x and y

Solving both equations to find value of x and y

`x+y= 18 ----(1)\\(4)/(7) y-5x= 14 ------(2)`

From equation 1 we can find value of x and put in equation 2 i.e

x=18-y

Putting the value of x in equation 2

`(4)/(7)y-5(18-y)=14\\Solving:\\\\(4)/(7)y-90+5y=14\\(4y-90*7+5*7y)/(7)=14\\ (4y-630+35y)/(7)=14\\4y+35y-630=14*7\\39y=98+630\\y=728/39\\y=18.6`

Now finding x

`x=18-y\\x=18-18.6\\x=-0.5`

So, Required numbers are x = -0.5 and y =18.6