Answer: 396/100
Step-by-step explanation:
Here is the equation:

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You need to get "x" by itself so minus 3 from each side

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Divide 8 by 2

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x=4
So each 4 is equivalent to 4
Lets check:

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So that means that Marcus practiced the piano for 4 hours and Donnel practiced for 7
There's a couple ways to do this. These look like special triangles to me. Which should be the 30 60 90 triangle's which have the same ratios for their legs. The legs will always be square root three and one and the hypotenuse of two - I can't see what I'm typing for some reason so I will finish in a comment
Answer:
3 and 5/16
Step-by-step explanation:
3+(2+8)2-:4*((1)/(2))^(4)=53/16