First you combine 8x and -2x which is -6x
and 5+-1=4
y=-6x+4
Look at the picture.
ΔZYX and ΔDYC are similar. Therefore the lengths of sides are in proportion:

DC = x
ZX = 16
DY = a
ZY = a + a = 2a
Substitute:

<em>multiply both sides by 16</em>

<h3>Answer: CD = 8</h3>
since its the zeros it should be x -/+ something
(x-1)(x+1)(x+4)
multiply for standard form
((x^2)-1)(x+4)
x^3-x
+ x^2 -4
x^2 + x^2 -x -4
(6x+10)°=(6x+10)°[vertically opposite angle]
now,
6x+10+10x+10=180°[being cointerior angle]
16x=180-20
x=160%16
x=10°