Cost of fencing a rectangular field is Rs, 1200. If the cost per m is Rs. 10, find the perimeter of the specific field. Please show working too.

Can someone explain the elimination method to me for this problem?

Aline parallel to a triangle's side splits ab into lengths of x - 5 and x + 2. the other side, ac, is split into lengths of x and x + 12. what is the length of ac? a) 12 b) 24 c) 36 d)

Prove that the sum of two consecutive exponents of the number 5 is divisible by 30.if two consecutive exponents are 5n and 5n + 1, then their sum can be written as 30.