To find out how old the twins were that were in the recital you need to be able to interpret a stem and leaf plot. The number of the left gets placed with each number on the right to create a number in the data set. See the key for an example. This means there were 2 people that were 5 years old making them the twins!
<span>Melvina's age is = x, Bettina's age is = 3x
the equation is
x + 20 = 3x - 20
subtract 3x from both sides
-(3x) + x +20 = 3x - 20 - (3x)
-2x + 20 = -20
subtract 20 from both sides
-2x + 20 - (20) = -20 - (20)
-2x = - 40
divide both sides by -2
(-2x)/-2 = (-40)/-2
x = 20
Melvinas age is 20 and Bettinas age is 60</span>