Robert and elaine ran around the high school track during gym class. robert ran 1/2 of the way around the track in 5/6 minute. later in the day, elaina ran 3/4 of the way around the track in 9/10 minute. when they meet after school, robert claims that he can run father in a minute than elaina. is he correct or incorrect? explain your reasoning. unpack the problem: make a plan: solution: look back and explain:

Answer

Incorrect

Explanation

Unpack the problem:

Let the distance round the track to be X.

Speed is the ratio of distance to time.

Robert run a distance of (1/2)x

Elaine run a distance of (3/4)x

Make a plan:

Finding the speed of each.

Compare their speeds to determine who ran faster than who.

Solution:

Robert's speed =(1/2)x/(5/6)

=1/2×6/5x

= (3/5)x

= 0.6x

Elaine's speed = (3/4)x/(9/10)

= (3/4)×(10/9)x

= (5/6)x

= 0.83333x

Elaine ran faster than Robert.

Look back and explain:

0.83333x > 0.6x

Elaine's speed is higher than Robert's speed.

This shows that Elaine ran faster than Robert.

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations: