3x+2y=18 , 8x+6y=50 if x represents the cost of a birthday card and y represents the cost of a you note how much does each birthday card cost

(-9x-6y=-54) +(8x+6y=50)= -x=-4; x=4
3(4)+2y=18
12+2y=18
2y=6 ; y=3
Each birthday card costs 4

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

first one because it can't have a fraction in it

step-by-step explanation: