Two models of the Lakhta tower are mathematically similar. The smaller model has a height of 15cm and the larger model has a height of 20cm. If the smaller model has a mass of 108g, what is the mass of the larger model?

Calculate

Expand and simplify: (3x+1)(x+2)(x+3)

Rewrite x^{2} – 6x + 17 in the form (x-a)^{2} + b

Solve (x+1)(x-2) = 40