Question

Jackie has 4 red blocks and 5 blue blocks that weigh 75 ounces. Sam has 4 red blocks and 4 blue blocks that

weigh 65 ounces. How much does the red block weigh? How much does the blue block weigh? Write a let
statement for each variable below, write a system of equations, then solve the system.

Answer 1

(6.25, 10)

Explanation:

red = x. blue = y

Jackie: 4x + 5y = 75

Sam: 4x + 4y = 65

Solving by elimination

4x + 5y = 75

4x + 4y = 65

--------------------

(4x + 5y = 75) × -1

-4x - 5y = -75

-4x - 5y = -75

4x + 4y = 65

------------------------

-y = -10

÷-1 ÷-1

--------------

y = 10

4x + 4y = 65

4x + 4(10) = 65

4x + 40 = 65

-40 -40

--------------------

4x = 25

÷4 ÷4

-------------

x = 6.25

(6.25, 10)

Each red block weighs 6.25 ounces.

Each blue block weighs 10 ounces.

I hope this helps!