Set up a system of equations. d + q = 75 .1d + .25q = 14.25
Multiply the first equation by -.1 so that the "d's" will cancel. -.1d -.1q = -7.5 .1d +.25q = 14.25 Now add the two equations together .15q = 6.75 divide both sides by .15 q = 45 There are 45 quarters in the jar