Boxes weigh 280g, packages weigh 200g
Explanation
3b+2p=1240
5b+7p=2800
Since it’s a system of equations we can use substitution or elimination.
The following is elimination
(-5) 3b+2p=1240 —->. -15b-10p=-6200
(3) 5b+7p=2800 ——> 15b+21p=8400
11p=2200 then divide, so p=200
Then substitute p in an equation
3b+2(200)=1240 1240-400=840
3b=840 then divide
B=280
