Question

Sally wants to make orange paint with yellow and red.To make Orange Sally needs 1lb of red and 3 lbs of yellow. She decides its not enough paint. She wants 40 lbs of orange paint. Write an equation to show what she needs to do to have the right amount of orange paint.

Answer 1

one "batch" of paint (1 red, 3 yellow) is 4 lbs.
So, if she needs x batches of paint,
1x + 3x = 40