Question

Solve the following
(a) If x+y=12 and xy= 27, find the value of x'+​

Answer 1

Question :-

If x+y=12 and xy= 27, find the value of x and y .

Answer :-

Given :-

• x + y = 12
• xy = 27

To find :-

• The values of x and y

Solution :-

x + y = 12

$\implies$ x = 12 - y

• substitute the value of x in the equation xy = 27

$(12 - y)y = 27 \\12y - {y}^{2} = 27 \\ 12y - {y}^{2} - 27 = 0 \\{y}^{2} - 12y + 27 = 0 \\{y}^{2} - 9y - 3y + 27 = 0 \\y(y - 9) - 3(y - 9) = 0 \\(y - 9)(y - 3) = 0 \\ y = 9 \: or \: y = 3$

x = 12 - y

so ,

》 If y = 9 $\implies$ x = 12 - 9 = 3

》If y = 3 $\implies$ x = 12 - 3 = 9