What is the complex conjugate of 12i ?

Look at attachment. has all info needed. need

Hillel is juggling flaming torches to raise money for charity. his initial appearance raises $500\$500 $500 , and he raises $15\$15 $15 for each minute of juggling performance. the amount rr r of money hillel raises is a function of tt t , the length of his performance in minutes. write the function's formula.

Divide. write in the simplest form. 4 1/6 divided by 10