f(x)= -x^2+4 plotted vertex (0,4)
240, you just add a zero to 24, I don't know what you mean by zero the hero of 4 square, hope this helps!
The median of the triangle is a segment that connects the vertex of the triangle to the midpoint of the side opposite to the vertex. <span>The altitude of the triangle is a segment that connects the vertex of the triangle to the side opposite to the triangle, which intersects that side at exactly 90°.</span>
Given equation is y=2x+7 and 
Let's simplify the 2nd equation
before we can start graph so that calculation will be easy

multiply both sides by 2 to cancel out fractions

y=2x+7
which is exactly same as the first equatoin so graph of both will be exactly same and solution will be infinitely many solutions.
y=2x+7 has y-intercept 7 so first point will be (0,7). Slope is 2 so rise 2 unit up then 1 right and graph the new point.
-3x - 3.2 no
-1.2-8 no
-1.2x-3.2 yes
-1.2x+3.2 no