What is the number 7,938 simplified

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

Write the expression as a constant , a single trigonometric function, or a power of a trigonometric function. sin x cos x/ tan x

[15 points]find the least common multiple of the expressions: 1. 3x^2, 6x - 18 2. 5x, 5x(x +2) 3. x^2 - 9, x + 3 4. x^2 - 3x - 10, x + 2 explain if possible