Find the discriminant and determine the number of real roots for each equation. Show steps. -9x^2 + x - 7 = 0

How many days was the temperature above 90 degrees?

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

One of the complementary angles is 4 degrees mor than the other. find the angles (recall that complementary angles are angles whose sum is 90 degrees.) which of the following can not be used to solve the problem if x represents one of the angles? a. 2x-4=90 b. 2x+4=90 c. x+4=90