Answer:
y - x = 7
y -2x = 11
Explanation:
y - x = 7
y - 2x = 11
Multiply the the first equation by -1 and then add the equations together
-y + x = -7
y -2x = 11
-x = 4 Multiply both sides by -1
x = -4
Substitute in -4 for x in either of the two original equations to solve for y
y - x = 7
y - (-4) = 7
y + 4 = 7 Subtract 4 from both sides
y = 3
The solution is the ordered pair (3,-4)
Here is how I came up with my equations. I know that I want y to be -4 and x to be 3.
y = mx + b If I select m to be 1, then I solve for b to write the equation
3 = (1)(-4) + b
3 = -4 + b Added 4 to both sides
7 = b
My equation is now:
y = (1)x + 7
or
y = x + 7
I changed the form by subtracting x from both sides so that it is friendly to use elimination to solve.
y - x = 7
For my second equation, I select 2 to be my m
y = mx + b
3 = (2)(-4) + b Solve for b
3 = -8 + b Add 8 to both sides
11 = b
y = mx + b
y = 2x + 11 and then subtracted 2x from both sides to make the equation friendlier to use elimination to solve.
y - 2x = 11
There is a lot going on here. I hope that it makes sense. If it doesn't make sense, it is me and not you.
Helping in the name of Jesus.