Simplification Ques 12
Question-
$(2 \sqrt{392}-21)+(\sqrt{8}-7)^{2}=(\text { ? })^{2}$
(1) 4
(2) -4
(3) 12
(4) 2
(5) 6
Show Answer
Correct Answer: (5)
Solution:(5)
$(?)^{2}=(2 \sqrt{392}-21)+(\sqrt{8}-7)^{2}$
$(?)^{2}=(2 \sqrt{7 \times 7 \times 2 \times 2 \times 2}-21) +(8+49-2 \times 7 \sqrt{8})$
$(?)^{2}=28 \sqrt{2}-21+57-28 \sqrt{2}$
$(?)^{2}=36$
$\therefore ?=\sqrt{36}=6$
BETA
