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Mathematics: Post your doubts here!

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cube root 7100 can be written as cube root 71 * 100
ths can further be written as surd form like 10 cube root 71
using ur expansion 71 =( 8 - 9x )
replace this in the surd form expression...it will become 10 cube root ( 8 - 9x )

PS i need the expansion to get the result x=0.1
upload it plz. im too lazy to work tht out.
In the marking scheme they are writing cube root of 7100 as cube root of 7.1 and cube root of 1000. I think.
Cube root of 1000 would be equal to 10.
So, giving 10 cube root of 7.1..
Than making 7.1=( 8 - 9x ) giving x=0.1
but how did they get 10 cube root of ( 8 - 9x )?!

In your method 71 =( 8 - 9x ) give x= -7

btw, I am asking HOW they got the x value as 0.1 there. After getting the x value, I know how to proceed. Getting the x value correctly is the problem.
 
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In the marking scheme they are writing cube root of 7100 as cube root of 7.1 and cube root of 1000. I think.
Cube root of 1000 would be equal to 10.
So, giving 10 cube root of 7.1..
Than making 7.1=( 8 - 9x ) giving x=0.1
but how did they get 10 cube root of ( 8 - 9x )?!

In your method 71 =( 8 - 9x ) give x= -7

btw, I am asking HOW they got the x value as 0.1 there. After getting the x value, I know how to proceed. Getting the x value correctly is the problem.
yeah i jst solved it without knwin the expansion.
its 7.1 * 1000 sorry. i took it for square root by mistake :p
it said use the expansion from part (i) so u should assume the expansion to be equal to cube root 7100 which is now equal to 10 cube root 7.1

so :

10 cube root 7.1 = 10 cube root (8 -9x)
cancel 10 cube root on both side

7.1 = 8 - 9x
x = 0.1
 
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yeah i jst solved it without knwin the expansion.
its 7.1 * 1000 sorry. i took it for square root by mistake :p
it said use the expansion from part (i) so u should assume the expansion to be equal to cube root 7100 which is now equal to 10 cube root 7.1

so :

10 cube root 7.1 = 10 cube root (8 -9x)
cancel 10 cube root on both side

7.1 = 8 - 9x
x = 0.1
Ms me to 71 hai 7.1 nai .-.
 
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yeah i jst solved it without knwin the expansion.
its 7.1 * 1000 sorry. i took it for square root by mistake :p
it said use the expansion from part (i) so u should assume the expansion to be equal to cube root 7100 which is now equal to 10 cube root 7.1

so :

10 cube root 7.1 = 10 cube root (8 -9x)
cancel 10 cube root on both side

7.1 = 8 - 9x
x = 0.1
Using expansion from part (I) means I should assume that 10 cube root of 7.1 is equal to cube root of 8-9x.
NOT: 10 cube root of 7.1 is equal to 10 cube root of 8-9x.
As part (I) is for only cube root of 8-9x.
So how did that 10 come there? In your ans?..n the one given in marking scheme. -.-
 
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Using expansion from part (I) means I should assume that 10 cube root of 7.1 is equal to cube root of 8-9x.
NOT: 10 cube root of 7.1 is equal to 10 cube root of 8-9x.
As part (I) is for only cube root of 8-9x.
So how did that 10 come there? In your ans?..n the one given in marking scheme. -.-
cube root 7100 = cube root 8-9x
so 10 cube root 7.1 = 10 cube root 8-9x
in surd form
 
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