How many 3-letter sequences can be formed if the second letter must be a vowel (A, E, I, O, or U), and the third letter must be different from the first letter?

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

3 qrs + 3/2 xy hope this : /

step-by-step explanation:

the one below it is a function

1st part is 64,000,000

2nd part 500,000

step-by-step explanation: