Question

If x-y=5andxy=24 find the value of x+y

Answer 1

Answer:

first find value of x=5+y.......(1)

then, put the value of x in xy =24

we get, (5+y)*y=24

5y+y^2-24=0

y^2+5y-24=0

we get value of y=1

then, put the of y in eq (1),

x=5+1

x=6

I hope this answer help you

Answer 2

Answer:

x + y = 11

Note:

★ (a + b)² = a² + 2ab + b²

★ (a - b)² = a² - 2ab + b²

★ a² - b² = (a + b)(a - b)

★ (a + b)² = (a - b)² + 4ab

★ (a - b)² = (a + b)² - 4ab

★ (a + b)² + (a - b)² = 2(a² + b²)

★ (a + b)² - (a - b)² = 4ab

★ (a - b)² - (a + b)² = -4ab

Solution:

Given: x - y = 5 , xy = 24

To find: x + y = ?

Now,

=> (x + y)² = (x - y)² + 4xy

=> (x + y)² = 5² + 4•24

=> (x + y)² = 25 + 96

=> (x + y)² = 121

=> x + y = √121

=> x + y = 11

Hence,

The required answer is 11 .