Ok let’s take this example:5 tins of soup have a total weight of 1750 grams. 4 tins of soup and 3 packets of soup have a total weight of 1490 grams. Work out the total weight of 3 tins of soup and 2 packets of soup.
To get started, we must highlight and separate the different equations given1) 5 tins = 1750g2) 4 tins + 3 packets = 1490g3) 3 tins + 2 packets = ?
To answer the question we must first find the values of 1 tin and 1 packet each Using equation 1) we know that:5 tin = 1750g1 tin = 1750g/5 (Devide by 5 both side)1 tin= 350g
Substituting this in equation 2) gives:4 x 350g(tin) + 3 packets = 1490g1400 + 3 packets = 1490g3 packets = 90g (-1400 both sides)1 packet = 30g ( devide by 3 both sides)
Finally, substituting all values in equation 3) gives:(3 x 350g)+ (2 x 30g) = ?1050g + 60g = ?=1110g