1. make an equation 4x+7(20) = 5(x+20) 2. multiply the numbers and distribute 5 through the parenthesis 4x+140 = 5x+100 3. move variables to the left side and change its sign and move constant to the right side and change its sign 4x-5x = 100-140 4. collect the like terms and calculate the difference -x = -40 5. change the signs on both sides of the equation x = 40 he needs to use 40 pounds of the cheaper coffee. hope this helped!
