Question 4360
You are close, but you don't need a y.  Just an x.  See if the following will be some help to you.

Almonds - $4.27
Amount in lbs = x
Total of Each - 4.27x

Cashews - $3.10
Amount in lbs =  60-x
Total Cost of each = $3.10(60-x)

Mixture =$3.49
Amount in lbs = 60
Total Cost of each = 3.49(60)

4.27x + 3.10(60-x) = 3.49(60)

4.27x + 186 - 3.10x = 209.40

1.17x = 23.40
x=20

Check your answer

4.27(20)85.40
$3.10(60-20)$3.10 x 40 = 124.00
85.40 + 124.00 = 209.40