Janet and Samantha love watches. Janet owns 15 watches and she buys 2 new watches each month.

Samantha owns 9 watches and she buys 3 new watches each month.

Write and solve an equation to find how many months it will take for them to have the same amount of watches.

Use m as the variable for your equation.

no

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