Give the value or evaluate the value of factorial of root 2

Solve the system of equations. y= 2x y= x^2 - 15

Need showing work for this problem 56.25 ×25.80

Which of the following would be a reasonable estimate for the weight of a pencil? a. 1 × 10^-20 lb b. 1 × 10^20 lb c. 1 × 10^2 lb d. 1 × 10^-2 lb