B.
Since he had to subtract 7 to get to -3, you would have to find the expression that would yield that answer.
Hope this helps!
The first method is substitution. This is when the x or y value that is known is substituted into one of the equations. This should be done when you can easily see or find the x or y value.
Example: x = 3, and x + 8y = 30.
The x was given in the first equation (x = 3), and can therefore be substituted into the other equation to find y.
The next method is elimination. This is when you add the two systems together and eliminate either the x values or the y values. This should be done when there are opposite signs of the same number in both equations.
Example: y - 3x = 24, and 2y + 3x = 7
In the first equation you have -3x, and in the second you have 3x. If you were to add the two equations, the x values would cancel out and you would be left with:
y + 2y = 24 + 7
And then you could solve for y.
The last method is to graph both equations and to see at which point the lines intersect.
I’m pretty sure that the slope of that function is 5/8
