Question

If 81y2 -k=(9y+1/2)(9y-1/2) then the value oF k is

Answer 1

Answer:

The answer is 1/4

Step-by-step explanation:

step1:

Firstly observe the R.H.S it is in the form of

$a {}^{2} - b {2}$

I.e.,(a+b)(a-b)

step2:

$81y {2} - k = (9y) {2} - (1 \div 2) {2}$

step3:

$81y {}^{2} - k = 81y {}^{2} - (1 \div 4) \\ k = 1 \div 4 \\ k = 0.25$