1 cubic metre of concrete has a weight of 2400 kg 15% of the concrete is water the rest of the ingredients of concrete are cement, sand and stone the weights of these ingredients are in the ratio 1:2:5 work out the weight of cement, sand and stone in 1 cubic metre of concrete

1. isolate the variable, in this case, d. subtract 35.5 on both sides of the equation.2. 52 subtracted by 35.5 is 16.53. therefore your answer would be d= 16.5this is the basics of pre algebra, isolating variable through adding, subtracting, multiplying, and dividing, if you have any other questions to ask just comment!

Aand b are correctly balanced reactions. they have the same number of atoms in both sides of the reaction