Daniel L. answered • 04/20/19

Certified in tutoring/academic coaching by the National Tutoring Assn.

You need to translate the English into math.

You are asked to find the mass of bricks so that is your unknown.

Let X = the mass of bricks.

The mass of bricks and the load = 11600.

So the empty lorry (the British word for a truck) is 11600 - X.

If the bricks weighed 100 kg, then the truck would weigh 11500, right?

The bricks weigh 3 times as much as the empty truck.

So 3 times the weight of the truck equals the weight of the bricks.

3(11600-X) = X

Now solve the equation by distributing 3 over the contents of the parentheses. Then get all X's on the right side. Then divide both sides by the coefficient in front of the X on the right and you'll determine what X equals.

Good luck!

Dan