b= bracelet
n= necklace= 2 times as long as bracelet= 2b
32" string= total length available
He's making 2 bracelets & 1 necklace
EQUATION:
32>n + 2b
substitute n=2b for n in the equation
32>2b + 2b
combine like terms
32>4b
divide both sides by 4
8>b each bracelet must be less than 8"
substitute 8>b to find n
n= 2b
n= 2(8)
n= 16 necklace must be less than 16"
Check:
substitute answers in original equation
32>n + 2b
32>2(8) + 2(8)
32> 16 + 16
32=32
Hope this helps! :)