The point slope form of a straight line is y-y1 = m(x-x1)
y -(-3) = -7(x-5)
y + 3 = -7(x-5)
y = -7x + 35 - 3
y = -7x + 32
#3 is correct at 120.4
#4 is 15/8...because 3/4+3/4=6/4 (for 20 doors) plus 3/8 (which is half of 3/4 for 5 more doors) equals 15/8 gallons or 1.875 gallons
#5 is $812.50 because if 50 shares cost $125, 325 shares (125×6.5) equals 812.50
Plug in 0 into x of the equation y=2x+3, solve it, then take that answer and use that as your y then plug in the answer for y and solve for x. (i realized i am very bad at explaining this over this. Sorry I tried)
As they are written, they are all linear. I think you meant for the third one to be y=x^2. if that is true then y=x^2 is a quadratic and therefore is the answer
