Two models of laptop computers are shipped in crates. one crate weighs 650
pounds and contains 50 of the smaller model and 75 of the larger model. another crate weighs 550 pounds and contains 100 of the smaller model and 25 of the larger model. how much does each model weigh?

Weight=smallertotalweight+largertotalweight

smallertotalweight=weight times how many
largertotalweight=weight times how many

lets call them s and l
smaller and larger

650=50s+75l
and
550=100s+25l
simplfiy the m all by dividing by 5

130=10s+15l
110=20s+5l
divide by 5 again

26=2s+3l
22=4s+l

we can eliminate the s's

multiply first equatn by -2 and add to first

22=4s+l
-52=-4s-6l +
-30=0s-5l

-30=-5l
divide both sides by -5
6=l

input back
22=4s+l
22=4s+6
minus 6
16=4s
divide 4
4=s

each smaller model weighs 4 pounds
larger weighs 6 pounds