Paul N. answered • 04/13/13

Learning your way

X intercepts are where the line crosses or touches the x axis thus y=0

for y=3(x+3) a straight line that crosses the x axis at only one point, so when you solve for x with y=0, x then equals -3 thus you get ordered pair (-3,0)

But what I think you wished for y=3(x+3)^{2}

Again solve for x with y=0, 0/3=(x+3)(x+3)=x^{2}+6x+9 solving the quadratic you get two equal solutions -3 and -3 which is of course only one actual solution so if you graph it you have a parabola that only touches but not crosses the x axis at the ordered pair (-3,0)