Spot & correct the error

Sipho writes: $\tfrac{1}{4}+\tfrac{1}{6}=\tfrac{2}{10}$. Identify the mistake and write the correct sum.

Anika writes: $\sqrt{5^{2}+12^{2}}=5+12$. Identify the mistake and give the correct value.

Nomsa writes: $6(3x-4)=18x-4$. Identify the mistake and write the correct expansion.

Ayanda writes: $2(5x-7)=10x-7$. Identify the mistake and write the correct expansion.

Anika is asked for the AREA of a 7 cm by 6 cm rectangle and writes: Area $=2(7+6)=26$ cm$^{2}$. Identify the mistake and give the correct area.

Anika writes: $3(8x-9)=24x-9$. Identify the mistake and write the correct expansion.

Zinhle writes: $6(3x-9)=18x-9$. Identify the mistake and write the correct expansion.

Kagiso says the hypotenuse of a right triangle with legs 6 cm and 12 cm is 18 cm. Identify the mistake.

Sipho writes: $6m^{2}=600$ cm$^{2}$. Identify the mistake and give the correct value.

Zinhle writes: $4x+5x=9x^{2}$. Identify the mistake and write the correct simplification.

Sipho says the hypotenuse of a right triangle with legs 6 cm and 12 cm is 18 cm. Identify the mistake.

Zinhle says the hypotenuse of a right triangle with legs 5 cm and 12 cm is 17 cm. Identify the mistake and give the correct length.