How to do x squared - 2x plus y squared = 80

Heidi must correctly answer at least 80% of the questions on an exam to advance to the next level in her online course. Heidi has already correctly answered 26 questions and incorrectly answered 4 questions.

There are 25 counters in a bag. 12 are red, 5 are green and the rest are white. A counter is chosen at random. Work out the probability that it is white.

65 minus 20 plus 100 minus 60 is?

Find d2y/dx2 in terms of x and y if (x^2) - (y^2) = 16.

Simplify 5√x^20 1. x4 2. x8 3. x3 (5√x) 4. x (5√x3)

What is the simplest form for 3/8

How is the number 6.24 x 10-4 expressed in regular numbers?

03: Use substitution to show that x = is a solution to the equation 4 cos (x) - 1 = 0. Show all of your work (do not use a calculator)

Capacity of coffee mug

write the standard form of the equation of the circle that passes through the origin, (2.8,0), and (5,2)