Question

Assignment
1) if 3x-y= 10 and x-3y=-2, find the value
of x-y.​

Answer 1

Answer:

2

Step-by-step explanation:

I'll be using Substitution Method for my explanation.

3x - y = 10 can be rearranged as y = -10 + 3x.

For the second equation, substitute y value and solve for x, which would look like this:

x-3(-10 + 3x) = -2

x + 30 - 9x = -2

-8x = -32

x = 4

Substitute 4 for x in either equation and you should get 2.  I'll show both:

Equation 1: 3(4) - y =10

12 - y = 10

- y = -2

y = 2

Equation 2:  4 - 3y = -2

-3y = -6

y = 2

4-2 = 2

Answer 2

Answer:

2

Step-by-step explanation:

3x - y = 10 -------> (1)

x - 3y = -2 × (3)

3x - 9y = -6 --------> (2)

from (1) and (2),

3x - y = 10

3x -9y = -6

(-) (+) (+)

0 + 8y = 16

which implies, y = 16/8 = 2

then substitute y value in (1), then,

3x - 2 = 10

3x = 10 + 2

x = 12/3 = 4

Therefore, x - y = 4 - 2 =2