Question

if a number is doubled then which of the following is a correct statement?
a) it's cube is two times the cube of the given number
b) it's cube is three times the cube of the given number
c) it's cube is six times the cube of the given number
d) it's cube is eight times the cube of the given number​

Answer 1

Answer:

This implies that

x2+2ax=4x−4a−13

or

x2+2ax−4x+4a+13=0

or

x2+(2a−4)x+(4a+13)=0

Since the equation has just one solution instead of the usual two distinct solutions, then the two solutions must be same i.e. discriminant = 0.

Hence we get that

(2a−4)2=4⋅1⋅(4a+13)

or

4a2−16a+16=16a+52

or

4a2−32a−36=0

or

a2−8a−9=0

or

(a−9)(a+1)=0

So the values of a are −1 and 9.

Answer 2

$\underline{\boxed{\bold{Question}}}$

if a number is doubled then which of the following is a correct statement?

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Option -A It's cube is two times the cube of the given number

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possibility of one cube= (1,2,3,4,5,6)=6

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possibility when it double =6×6=36

(1.1, 1.2 ,1.3 ,1.4 ,1.5 ,1.6)

(2.1 ,2.2 ,2.3 ,2.4 ,2.5 ,2.6)

(3.1 ,3.2 ,3.3 ,3.4 ,3.5 ,3.6)

(4.1, 4.2 ,4.3 ,4.4 ,4.5 ,4.6)

(5.1, 5.2 ,5.3 ,5.4 ,5.5 ,5.6)

(6.1 ,6.2 ,6.3 ,6.4 ,6.5 ,6.6)

[Hope this helps you.../]