Question

If 12x + 10y =9 and 10x + 12y = 5, then x – y =?​

Answer 1

Answer:

subtract like this

12x+10y-(10x+12y) = 9-5

12x+10y-10x-12y = 4

2x-2y= 4

take 2 common frol l.h.s

2(x-y)= 4

x-y = 4/2

x-y = 2

Answer 2

Answer:

x-y=2

Step-by-step explanation:

First let's find out the value of X and Y.

For that we will use a system.

• 12x + 10y=9
• 10x + 12y=5

• x=(9-10y)/12
• 10x + 12y=5

Let's copy the 2nd equation (10x + 12y = 5) and replace the value of X found in the 1st equation [x = (9-10y) / 12].

10x + 12y=5

10[(9-10y)/12]+ 12y=5

(90-100y)/12 +12y=5

90-100y + 144y=60

-100y + 144y=60-90

44y= -30

y=-30/44

y=-15/22

To find the value of X, we substitute the value of Y in any of the equations.

10x + 12y=5

10x + 12(-15/22)=5

10x - (180)/22=5

10x -90/11=5

10x=5 + 90/11

10x=(55+90)11

10x=145/11

x=(145/11)10

x=145/11 X 1/10

x=145/110= 29/22

To end x-y:

29/22 - (-15/22)

29/22 + 15/22

(29+15)/22

44/22

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