Question

If 2 m - n = 4, find the numerical value of 2 m + n from the given expression.

Answer 1

Answer:

Step-by-step explanation:

(2m +n)² - (2m -n)² = 4 x 2m x n       [∵ (a+b)² - (a-b)² = 4ab]

(2m + n)² = 8mn +16

               = 8m(2m -4) + 16

               = 16 m² - 32 m + 16

                = 16 (m² -2m +1)

                = 16(m-1)²

∴ 2m + n = 4(m-1)