Questions - 1. if one zero of the polynomial 2x^2 - 5x - (2k + 1) is twice the other, then find both the zeroes and the value of k.
2. solve for x and y :
(a + 2b)x + (2a - b)y = 2
(a - 2b)x + (2a + b)y = 3
3. Find 'a' and 'b'for which this equation have infinite solutions.
(a + b)x - 2by = 5a + 2b + 1
3x - y = 14
4. A boat goes 20 km upstream and 44km downstream in 10 hr. In 13hr, it can go 40 km upstream and 55km downstream . determine the spped of stream and that of boat in still water.
No need to send solution of last, just tell whether the answers are one of the 2 and 8, but please tell the method, and how to tackle some similar questions like the last one.
Please give the answers step by step and not for only points.