Xác định m để hàm số y = -2x^3+3mx^2-1 luôn nghịch biến

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

One positive number is 9 more than twice another. if their product is 95, find the numbers

Ahiker stands at an unknown elevation before he ascends 2 miles up a mountain to an elevation of 9 miles. find the elevation of the hiker before his ascent.