Mr. Dunston and Mr. Dolland spent $45 all
together. Mr. Dunston and Ms. Campbell
spent $65 all together. If Ms. Campbell spent
3 times as much as Mr. Dolland, how much
did Mr. Dunston spend?

Mr. Dunston spend is $35.Given:Mr. Dunston and Mr. Dolland spent $45 all together.Mr. Dunston and Ms. Campbell spent $65 all together. If Ms. Campbell spent 3 times as much as Mr. Dolland.Let x , y , z be spend of dunston ,dolland and campbell.x + y = 45x + z = 65z = 3*yx + 3y = 65on substracting x + y = 45 and x + 3y = 65 we get,x + y - x - 3y = 45 - 65-2y = -202y = 20y = $10.substitute y value,x + 10 = 45x = 45 - 10x = $35Therefore Mr.Dunston spend $35.Learn more about the spend here:https://brainly.com/question/14073329#SPJ1