Please help by showing steps!?

Question

Solve the system by graphing if possible.

{x-y=8}

{2x+y=7}

a.(-5,-3)

b.(5,3)

c.(5,-3)

Answer 1

A really fast way to get the solution is with QuickMath.  Just cut and paste the equations into the Advanced mode of the Equation Solver (remove the braces) and it gives

x = 5

y = -3

as the solution.

I'm not suggesting that you not do the solution by hand as above (you'll probably need to know how to do that on a test) but QuickMath is a good way to check the answer you get by other methods.

Answer 2

b. (5,-3)

x - y = 8

5 - (-3) = 8

5 + 3 = 8

8 = 8

2x + y = 7

2(5) + - 3 = 7

10 -3 = 7

7 = 7

Answer 3

x - y = 8

2x + y = 7

--------------------[add]

3x = 15

=> x= 15/3 = 5

now, 5 - y = 8

=> - y = 8 - 5

=> - y = 3

=> y = - 3

ANSWER:

x = 5

y = -3

So, c.(5,-3) is ur answer