Question

( (3) sqrt{2401}=sqrt{7^{x}} )
( sqrt{7 times 7 times 7 times 7}=sqrt{7^{x}} )
( sqrt{7^{4}}=sqrt{7^{x}} )
Squaring both sides ( 7^{4}=7^{x} )
( Rightarrow x=4 )
(9) ( a=2, b=1, c=3 ) ( begin{aligned} & a^{2}+2left(b^{2}+c^{2}right) =&(2)^{2}+2left(1^{2}+3^{2}right) =& 4+2 times 10=4+20=24 end{aligned} )
(5) ( quad 8=2 times 2 times 2=2^{2} times 2 )
( 12=2 times 2 times 3=2^{2} times 3 )
( 15=3 times 5 )
( 20=2^{2} times 5 )
tepat least sqi no. ( begin{aligned} & text { divisible } 8,12,15 text { and } & 20=2^{2} times 3^{2} times 5^{2} times 2^{2} &=90000 end{aligned} )

# 3. 12401 = V7* , then the value of x is (2) 3 (6) 4 (c) 5 (d) 6. 4. Find the value of a + 2(b + A), if b = 1, c = 3 and a = 2 is (2) 24 (b) 13 (c) 20 (d) 30 5. The least square number exactly divisible by 8, 12. 15 and 20 is (a) 900 (b) 1200 (d) 14400 (c) 3600

Solution