Proofs

A easy difficulty HSC math problem on contrapositive of multiples of 6 with full step-by-step solutions.

A medium difficulty HSC math problem on cubic sums bound a quartic term with full step-by-step solutions.

A hard difficulty HSC math problem on density of q in r with full step-by-step solutions.

A medium difficulty HSC math problem on difference of squares cannot equal 1 with full step-by-step solutions.

A hard difficulty HSC math problem on divisibility by 6: criterion and consequence with full step-by-step solutions.