(8/9)^2 is 64/81. Exponent is 2. Hope this help
Considering the place value of the digit 9, in the first number, the decimal value of 9 is thousands. In the second number, the decimal value of 9 is hundredths. The conclusion we are drawing is: The second decimal is 10 times larger than the first one
For the sake of showing work I will replace the empty space with an x like so...

To find out what x is you must cross multiply (aka butterfly)
***Image of this step is attached below
9*x = 10*90
9x = 900
Next divide 9 to both sides to finish isolating x. Since 9 is being multiplied by x, division (the opposite of multiplication) will cancel 9 out (in this case it will make 9 one) from the left side and bring it over to the right side.
9x ÷ 9 = 900 ÷ 9
1x = 100
x = 100
To make these fractions equivalent the empty spot must be 100

Hope this helped!
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