Lesson 125 of Doodles Do Algebra

lesson125doodlepoodlecToday your child will learn about a special case of solving for 2 unknowns: when you are given the sum and the difference between two numbers.

DoodlePoodle explains the process very well on the worksheet so I will not go into the details here.

Download Lesson 125 of Doodles Do Algebra HERE

Answers:

1. In this problem we help get your child started by setting up the two equations that come from the word problem.

The equations are

x+y=100

x-y=25

and when you solve for the unknowns, you get x=62.5 and y=37.5

2. The equations are

x+y=5.5

x-y=0.75

and when you solve for the unknowns, you get x=3.125 and y=2.375 (you can just as well do these problems as fractions instead of as decimals)