Let x = amount of high quality coffee bean
110 - x = amount of cheaper coffee bean
6x + 3(110 - x) = 4.91 * 110
open the parenthesis
6x + 330 - 3x = 540.1
6x - 3x + 330 = 540.1
3x + 330 = 540.1
subtract 330 from both-side of the equation
3x = 540.1 - 330
3x =210.1
Divide both-side of the equation by 3
x = 70.0
Therefore, amount of high quality coffee bean = 70 lbs
Amount of low quality coffee bean = 110 - x = 110 - 70 =40 lbs