Two numbers differ from 4and the products are 96find the number
Answers
Given
Two numbers differ from 4 and the products are 96
To find
Find the numbers
Solution
Let the numbers be x and y
According to the given condition
- x - y = 4 --(i)
- xy = 96 -----(ii)
from (i)
=> x - y = 4
=> x = 4 + y
Putting the value of x in equation (ii)
=> xy = 96
=> (4+y)y = 96
=> 4y + y² = 96
=> y² + 4y -96 = 0
Solve this by splitting middle term
=> x² -12x +8x -96 = 0
=> x(x-12)+8(x-12) = 0
=> (x-12)(x+8) = 0
Either
x = 12 or x = -8
By substitution method
By substitution methodsubstitute the both value value of x in equation (i)
In case : 1
if x = 12
=> x - y = 4
=> 12 - y = 4
=> 12-4 = y
=> y = 8
In case : 2
if x = -8
=> x - y = 4
=> -8 - y = 4
=> -8 - 4 = y
=> y = -12
Required numbers in case : 1
x = 12 and y = 8
Required numbers in case : 2
x = -8 and y = -12
Two numbers differ from 4and the products are 96
find the numbers =?
Let the two numbers be 'x' and 'y'.
According to question :-
x - y = 4 ___1)
and,
xy = 96 ___2)
From equation 1).
x - y = 4
x = 4 + y
➡ Put the value of 'x' in equation 2)
(4 + y)y = 96
4y + y² = 96
y² + 4y - 96 = 0
y² + (12-8)y - 96 =0
y² + 12y - 8y - 96 =0
y(y + 12) -8(y + 12) =0
(y - 8) =0
(y + 12) =0
y = -12
y = 8
➡ Put the value of y = 8 in equation 1).
x - 8 = 4
x = 4 + 8
x = 12
➡ Put the value of y = -12 in equation 1)
x -(-12) = 4
x + 12 = 4
x = 4-12
x = -8
• Hence the two numbers are '12' and '8' in case 1)
and
the two numbers are -12 and -8 in case 2)