Hey I need help on these 2 questions

What are the soultion(s) to the quadratic equation 40- x^2=0

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.

Which shows the correct solution of the equation 1/2a+2/3b=50, when b=30?