The sum of the digits of a two-digit number is 12. If the digits are reversed, the new number is 54 less than the original number. Find the original number.

93

Step-by-step explanation:

Let the digit in tens place be 'x' & digit in ones place be 'y'.

So , the original number =

According to the question , ......... .eqn(1)

When digits are interchanged ,

The new number formed =

According to the question , ............ eqn(2)

Solving eqn(2) further ,

Adding eqn(1) and eqn(3) ,

Putting the value of x in eqn(1),

∴ Original number = 93

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places

what are you trying find out?

step-by-step explanation: