Q4a) yes, the equation is a linear function as it is a straight line; it has a slope of 2 and a y intercept of (0,2).
b) no, the equation isn't a linear function as it takes the form of a parabola (x^2-bx).
Q5) y=x+6, y= x^2+6 and y=2x+6 go through the point of (0,6). This is because, if you substitute 0 for x in all the three equations, y is always equal to 6.
Q6) the line is a linear function because it is a straight line that has a slope and a y intercept. To figure out the equation of the line, you have two points, (-2,0) and (0,3). To no the gradient, you do 3-0 divided by 0+2, which is 3/2. Then, you choose on random point and substitute it in y=mx+b
3= 3/2*0+b
So you get 3=b
So, the equation of the line is y= 3/2x+3