Question

factorise and find the values of x square minus 4 y square when X equals to 4 and y equals to 2 ​

Answer 1

Answer:

answer is 0

Step-by-step explanation:

as given that x=4 and y=2

$x { }^{2} - 4y {}^{2} \\ putting \: the \: values \: of \: x \: and \: y \\ (4) {}^{2} - 4(2) {}^{2} \\ = 16 - 4(4) \\ = 16 - 16 \\ 0$

method no. 2: by factorization method

$x {}^{2} - 4y {}^{2} \\ applying \: the \: rule \\ x {}^{2} - y {}^{2} = (x + y)(x - y) \\ so \\ x {}^{2} - 4y {}^{2} = x {}^{2} - (2y) {}^{2} = (x + 2y)(x - 2y) \\ now \: aply \: the \: values \: of \: x \: and \: y \\ (4 + 2(2))(4 - 2(2)) \\ = (4 + 4)(4 - 4) \\ = (8)(0) \\ = 0$