Question

If the product of two number is 10 and the sum is 7 ,then the longest of the two number is​

Answer 1

5 units

Explanation:

Step one:

Given data

Le the first number be x

and the second number be y

So

x*y= 10-----------------1

and

x+y= 7-----------------2

from eqn 1

x= 10/y

put x= 10/y in eqn 2

`10/y+y= 7\\\\10/y= 7-y`

cross multiply we have

`10=y(7-y)\\\\10=7y-y^2`

rearrange

`y^2-7y+10=0`

the factors of the quadratic expression are

-5 and -2

`y^2-5y-2y+10= 0\\\\y(y-5)-2(y-5) =0\\\\y-2=0\\\\y= 2\\\\y-5= 0\\\\y=5\\\\`

The longest side is 5 units