Question 165563
Let x=amount of almonds needed
Then 40-x=amount of walnuts needed
($ understood)
Now we know that the value of the almonds (1.60x) plus the value of the walnuts (1.10(40-x)) has to equal the value of the final mixture (1.25*40), so our equation to solve is:

1.60x+1.10(40-x)=1.25*40  get rid of parens distributive
1.60x+44-1.10x=50  subtract 44 from each side
1.60x+44-44-1.10x=50-44  collect like terms
0.50x=6  divide each side by 0.5
x=12 lbs ------------------amount of almonds needed
40-x=40-12=28 lbs --------------------amount of walnuts needed

CK
1.60*12+1.10*28=50
19.2 + 30.8=50
50=50

Hope this helps---ptaylor