Tyrell and Channing both work at the same fast food restaurant. Channing works 5 hours and earns $42.75. Tyrell's earnings are modeled by the equation E = 8h, where h is the number of hours worked and E represents his total
earnings. Which of the following statements must be true?

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

the answer on e2020 was d.