Question

if 7 x + 9 Y equal to 42 and 9 X + 7 Y equal to 22 then find X and Y​

Answer 1

Answer:

Firstly we will add both the equations then we will subtract it

Step-by-step explanation:

7x +9y = 42

+

9x+7y = 22

Gives

16x + 16 y = 64

Now,

7x+9y=42

-

9x+7y=22

-2x+2y=20

Now,

16x+16y=64

16(x+y)=64

x+y=4

and

-2(x-y)=20

x-y= -10

Now solve both the equations by elimination method

which will give x=7 and y= -3

thanks

Answer 2

= 7x+9y=42........(1)

= 9x+7y=22........(2)

Adding equation (1) and (2), we get

= 7x+9y+9x+7y=42+22

= 16x+16y=64

= 16(x+y)=64

= x+y=(64/16)

= x+y=4......... (3)

Similarly subtract those two equations, we get

=(7x + 9y) - (9x + 7y) = 42 - 22

= - 2x + 2y = 20

= y - x = 10.......... (4)

From equations (3) and (4) , we get

=> x = (-3) and y = 7

Hope it will help you....

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