Use the following system of equations to select the appropriate response. Step 1 of the substitution Method to solve system of equations. use the second equation and solve for the x Variable.
A. x = y - 3
B. x = -y + 3
C. x = -y - 3
D. x = y + 3

Step-by-step explanation:

Given system of equations is,

8x + 10y = 120 -----(1)

x - y = -3 ------(2)

From the second equation,

x = y - 3 [Option A]

Now we substitute the value of x in equation (1) and solve for y,

8(y - 3) + 10y = 120

8y - 24 + 10y = 120

18y = 120 - 24

y = = 8

From equation (2)

x - 8 = -3

x = 8 - 3

x = 5

First set are parallel, second are perpendicular, third are perpendicular, fourth are neither.

*If you can't remember the rules, or want to check your answers, I would type them into a graphing calculator. It will easily tell you which category they're in. (desmos.com)*

Step-by-step explanation:

1. Same slope (6/5) = parallel

2. Reciprocal (flipped) slope, opposite signs

3. Reciprocal (flipped) slope, opposite signs

4. Neither, the slopes aren't the same or flipped

When you flip the slopes (3/4 becomes 4/3) and change a sign, the lines will always be perpendicular.

Hope it helps :)