TWICE A CERTAIN NUMBER IS SUBTRACTED FROM 9 TIME THE NUMBER.THE RESULT IS 21.FIND THE NUMBER.

let the no. is x

then 9x-2x=21
=>7x=21
=>x=3

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Let's assume the number is x.

Given that twice the number is subtracted from 9 times the number, we can write the equation:

9x - 2x = 21

Simplifying the equation:

7x = 21

To find the value of x, divide both sides of the equation by 7:

7x/7 = 21/7

This gives us:

x = 3

Therefore, the number is 3.

To find the number, let's assign a variable to it. Let's say the number is 'x'.

According to the given information, twice the number is subtracted from 9 times the number, and the result is 21. We can write this as an equation:

9x - 2x = 21

Simplifying the equation:

7x = 21

Now we can solve for 'x' by dividing both sides of the equation by 7:

x = 21 / 7

x = 3

Therefore, the number is 3.