Question

The sum of two numbers is 18, 5 times the number subtracted from 4 over 7 of the second number is 14 find the number​

Answer 1

First number x = -0.6

Second number y = 18.66

Explanation:

Let the first number = x

and Second number = y

Sum of two numbers is 18. We can write it in mathematical expression as:

`x+y=18`

5 times the number subtracted from 4 over 7 of the second number is 14. We can write it in mathematical expression as:

`(4)/(7)y-5x=14`

So, solving the equations simultaneously we can find value of x and y

Let:

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

Finding value of x from equation 1 and put it in eq(2)

`x+y=18\\x=18-y`

Put in equation 2

`(4)/(7)y-5(18-y)=14\\(4)/(7)y-90+5y=14\\(4y-90*7+5y*7)/(7)=14\\ (4y-90*7+5y*7)/(7)=14\\ (4y-630+35y)/(7)=14\\ (39y-630)/(7)=14\\39y-630=14*7\\39y-630=98\\39y=98+630\\39y=728\\y=18.66`

So, Value of y= 18.66

Now finding value of x, By putting value of y in eq(1)

`x+y=18\\18.66+x=18\\x=18-18.66\\x=-0.6`

So, First number x = -0.6

Second number y = 18.66