Question

A number consists of a 2 digit the digit at the tens place is twice that of the digit at unit place if 18 is subtracted. From the number the digits are reversed find the number.

please can you help me with this answer,:-)​

Answer 1

Answer:

21

Step-by-step explanation:

Let the one's place be y and tens digit be x.

then, Number = 10x + y.

∴ Given, (x) = 2y ∴5x=2y⋯(i)

But, if 18 is subtracted, then, number gets reversed

ie. 10y + x.

∴(10x+y)−18=10y+x

⇒10x+y−18=10y+x

⇒10x−x+y−10y−18=0

⇒9x−9y−18=0

⇒x−y−2=0 Putting (y= 5x/2)

x− 5x/2-2=0

2x-x-2=0

X=2

y=1

Answer 2

Answer:

Let the one's place be y and tens digit be x.

then, Number = 10x + y.

∴ Given, (x) = 2y ∴5x=2y⋯(i)

But, if 18 is subtracted, then, number gets reversed

ie. 10y + x.

∴(10x+y)−18=10y+x

⇒10x+y−18=10y+x

⇒10x−x+y−10y−18=0

⇒9x−9y−18=0

⇒x−y−2=0 Putting [y=

2

5x

]

⇒x−

2

5x

−2=0

⇒2x−x−2=0 ∴y=

2

x

y = 1

⇒x=2

∴ Number = 21

Step-by-step explanation:

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