Question

3x+2y=5xy and 3y-x=-9xy. Find the value of xy

Answer 1

Answer:

look

Step-by-step explanation:

in second equation

-x + 3y = -9xy

x=3y + 9 xy

now putting this value in first equation

3x + 2y = 5xy

3( 3y + 9xy ) + 2y = 5xy

9y + 27xy + 2y = 5xy

11y= 5xy - 27xy

11y= -22xy

0=-22xy/11y

0=-2x

x=0

and if x= 0

X x Y = 0

Answer 2

$\large\underline\pink{Given:-}$

• 3x+2y=5xy and 3y-x=-9xy.

$\large\underline\pink{To find:-}$

• Fine the value of xy ....?

$\large\underline\pink{Solutions:-}$

• 3x + 2y = 5xy ______(i)
• -x + 3y = -9xy ______(ii)

multiplying Eq. (i) by 1 and Eq. (ii) by 3, we get.

• 3x + 2y = 5xy ________(iii)
• -3x + 9y = -27xy _________(iv)

Subtracting Eq. (iii) from Eq. (iv).

${3x} \: + \: {2y} \: \: = \: \: {5xy} \\ {-3x} \: + \: {9y} \: \: = \: \: {-27xy} \\ \underline{ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: } \\ \: \: \: \: \: \: \: \: \: \: \: {11y} \: \: \: \: \: = \: \: \: {-22xy}$

$\: \: \: \: \: \leadsto \: \: x \: \: = \: \: \frac{-1}{2}$

putting the value x in Eq. (i)

3x + 2y = 5xy

3(-1/2) + 3y = 5 × (-1/2) × y

-3/2 + 2y = -5y/2

-5y - 4y = -3

-9y = -3

y = 1/3

Now, the value of xy.

xy

-1/2 × 1/3

-1/6

hence, the value of xy is -1/6.