Question

If 12x + 17y = 48 and 17x + 12y = 68 then what is the value of x-y​

Answer 1

Given

12x+17y=48.....×12

17x+12y=68.....×17

144x+204y=576

289x+204y=1156

−145x=−580

x=4

substitute x value in the 1st equation

12×4+17y=48

48+17y=48

17y=0

then

x−y=4−0=4

Answer 2

Step-by-step explanation:

ANSWER

12x+17y=48 ...(i)

17x+12y=68 ...(ii)

On adding (i) and (ii) , we get

29x+29y=116

29(x+y)=116

x+y=116÷29

⇒x+y=4 ....(iii)

On subtracting (i) from (ii) , we get

5x−5y=20

⇒x−y=4