Mary and ally earned 542 points together. Mary has half the number of points as Ally. Write an equation that could represent this situation.

Question

Let a represent the number of points Ally earned. 

Answer 1

Let x be the number of points Ally has.

 

Then Mary has half that number or x/2.

 

Together, they earned 542 points so:

 

x + x/2 = 542 => (3/2)x = 542 (3/2 can also be written as 1.5).