Okay so my maths teacher was running out the door when he gave us this. so yea he didnt explain! its equations

11:50
right 1) allyos are made of metals. the different alloyys are made using iron and lead. To make the first alloy 3 cubic cm of iron and 4 cubic centimetres of lead are used. the alloy weighs 65 grams.

a) let x grams be teh weight of 1 cubic centimetres of iron and y grams be the weight of 1 cubic centimetre of lead.

b) write down a second in x and y which satisfies this condition.
c)find the weight of 1 cubic centimetre of iron and the weight of 1 cubic centimetre of lead.

I gave approximate values for specific gravity for a easier approach to the problem


specific gravity:

ρ = m/V ===> m = ρ V

ρ iron = 7 g/cm³ ==> m(iron) = x *3 = 7*3 = 21 g

ρ lead = 11g/cm³ ==> m (lead) = y*4 = 11*4 = 44 g

3x + 4y = 65

m(iron) + m(lead) = 21 + 44 = 65 g