If you want to spend ALL your money on chicken, then you just divide:
$100 /$1.29 =~77.5 Lbs of chicken. That leaves you with:
$100 - [$1.29 x 77.5] =$0.02 cents.
If you wish to spend ALL your money on steak, then just divide:
$100 / $3.49 =28.65 Lbs of steak. That leaves you with:
$100 - [$3.49 x 28.65] =$0.01 cent !!.
If you wish to divide your money half and half, then you just divide $50 by the price of chicken and $50 by the price of steak. That will give you half of the above numbers that we got for $100.