Question

In a two-digit number the ones place digit is , if the sum of the digits is 9, then what will be the

expression for the two-digit number?​

Answer 1

Answer:

eighteen is the expression

Answer 2

$Let \: one's:place \:digit = x$

$Ten's \:place \:digit = 9-x$

/* Given sum of the digits is 9 */

$\red{Required \:two \:digit \: number }$

$= 10(9-x) + x$

$= 90 - 10x + x$

$= 90 - 9x$

Therefore.,

$\red{Required \:two \:digit \: number }$

$\green { = 90 - 9x }$

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