Q9 of 116 Page 6

If = 18, find the values of and.

x2 + = 18

Adding 2 on both sides, we get


x2 + + 2 = 18 + 2


x2 + + 2 × x × = 20


(x + )2 = 20


x + = 2


Given that,


x2 + = 18


Subtracting 2 from both sides, we get


x2 + - 2 × x × = 18 – 2


(x - )2 = 16


x - = 4


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