Tina Mixes pretzels that sell for $2 a lb with cereal that sells for $3 a lb. she wants to make an 8 lb mixture to sell for $2.50. write 2 equations to represent this info.

How many lbs of pretzels and how many lbs of cereal were used to make the 8 lb mixture?

pretzels --- p

cereal ----- c

p+c = 8
2p + 3c = 2.5(8)

re-write the first : c = 20 - p
sub into 2nd

2p + 3(20-p) = 20

easy to solve