Chapter 3 Linear Systems and Matrices - 3.2 Solve Linear Systems Algebraically - 3.2 Exercises - Problem Solving - Page 166: 61

$80$ pounds of peanuts and $20$ pounds of cashews are in the mix.

Let there be $x$ pounds of peanuts in a mix, then there are $100-x$ pounds of cashews in a mix. Then our equation is: $ 2.8x+5.3(100-x)=3.3\cdot100\\2.8x+530-5.3x=330\\-2.5x=-200\\x=80$ Thus there are $80$ pounds of peanuts and $20$ pounds of cashews in the mix.