Solve the system of linear equations

x + y = 4 and 2x + 3y = 0

solve this answer by using substitution. set the first equation to x=-y+4 then substitute -y+4 for x in the second equation.

2(-y+4) + 3y=0

-2y+8 + 3y=0

y+8=0

y=-8

now use -8 and solve for x

x+(-8)=4

x=12

i really do not know lamo this is great

if the eqn of the parabola is f(x) = (x-4)(x+2), we need to mult. this out to find the coordinates of the vertex.

then f(x) = x^2 + 2x - 4x - 8, and f(x) = x^2 - 2x - 8.

one way in which you can find the vertex is to calculate x = -b / (2a).   here, that comes to

        )

x = = 1.   f(1) = 1^2 - 2(1) - 8 = - 9.   vertex is at (1, -9).

        2(1) 

find another point on the curve:   let x=0, for which y=-8.   then (0, -8) is on the curve.   plot the vertex and this point and draw a smooth parabola thru both.

hope this