Questions in mathematics

Questions in mathematics

[Done] Can somebody help me with #8?

[Done] Solve for x: \[3x = 54\]

[Done] Find the square root of \(4 + 2\sqrt{3}\).

[Done] Write an algebraic expression for 91 more than the square of a number.

[Done] Decide whether the function is a polynomial function. If so, write it in standard form and state its degree, type, and leading coefficient. \[ h(x) = 19x^4 - 419x^2 + 18 \]

[Done] Given: \[ \cos A = \frac{\sqrt{21}}{5} \] \[ \sin A = \frac{2}{5} \] What is the exact value of \(\cos 2A\)?

[Done] Convert the decimal to a fraction.

[Done] Joel has twice as many CDs as Mariella has. Subtracting 7 from the number of CDs Joel has and dividing by 3 equals the number of CDs Blake has. If Blake has 25 CDs, how many CDs does Mariella have?

[Done] The sum of Kris and Victor's ages is 27 years. In 3 years, Victor will be twice as old as Kris will be. What are their present ages?

[Done] What is the perimeter of a triangle whose sides measure 6, 8, and 10 inches?