xy46 xz52 yz54 Find x y z This is supposed to be a 3rd grade

x+y=46

x+z=52

y+z=54

Find x, y, z. This is supposed to be a 3rd grade level problem, in the book x,y, and z are really a square, circle and triangle, respectively. How would you do it so an 8 year old would understand?

Solution

x + y = 46 ---> ONE
x + z = 52 ---> TWO
y + z = 54 ---> THREE

TWO - THREE :

(x + z) - (y + z) = 52 - 54
x + z - y - z = -2
x - y = -2 ----> FOUR

Look at ONE and FOUR :

x + y = 46
x - y = -2

Adding :

2x =44
x = 44/2
x = 22

x - y = -2
22 - y = -2
-y = -2 - 22
-y = -24
y = 24

y +z = 54
24 + z = 54
z = 54 - 24
z = 30

Solution :

x = 22 , y = 24 , z = 30