Question

find the value of (x-y) if 3x-y=11 and x-3y= 17​

Answer 1

Answer:

$\sf{x-y}=\sf{7}$

Step-by-step explanation:

• $\sf{3x-y=11}$ ...(1)
• $\sf{x-3y=17}$ ...(2)

We can tell by the structure,

• $\sf3x+x=4x$, $\sf-y-3y=-4y$

From the structure, we add them.

• $\sf4x-4y=28$

We now divide by the same number.

• $\sf\dfrac{4x-4y}{4} =\sf\dfrac{28}{4}$

$\sf\therefore\sf{x-y}=\sf{7}$