Find the value of x

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What is the image of c for a 90° counterclockwise rotation about a? (3, 7) (-1, 3) (7, 3)

Awater holding tank measures 105 m long, 50 m wide, and 8 m deep. traces of mercury have been found in the tank, with a concen- tration of 60 mg/l. what is the total mass of mercury in the tank? answer in units of kg.

How to write four times a number,minus 6,is equal to theee times the number+8 as an equqtion