You buy 5 shirts each having the same price. Write a variable expression for the total amount you spend on shirts. How much money do you spend on the shirt when each shirt costs $15? A. 5x; $75
B. 5x; $20
C. 5 + x; $20
D. 5 + 5x; $25

A.

⎡

⎢

⎣

1

2

3

⎤

⎥

⎦

=

⎡

⎢

⎣

x

2

3

⎤

⎥

⎦

B. ⎡

⎢

⎣

1

2

3

⎤

⎥

⎦

=

⎡

⎢

⎣

x

2

3

⎤

⎥

⎦

sorry the last two i cant find. i hope this helps.

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