Which equation does not represent a direct variation? Explain.

y = 3x + 2

Step-by-step explanation:

"When x is zero in a direct variation equation y will also be zero. ... Equations of the form y = kx + b where b is a number other than zero are not direct variation equations because when x is zero in any of these y is not zero. Normally direct variation equations are written as y = k•x or just y = kx."

in short, y = 3x + 2 can't be turned into y = kx

you could also immediately tell it's y = 3x + 2 because it includes + 2

answer:     true

step-by-step explanation:

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4