First you had to remove parenthesis first.

Multiply by the numbers.

Final answer 



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-Charlie
Answer:
20x30xH=7000
11.6666 , depends on how much you need to round it. if 2 sig figs, round it to 12.
Answer:

Step-by-step explanation:
If two lines are perpendicular, they create 4 90° angles. Meaning, in this case, that m<DBC = 90 and m<DBA = 90.
We're given that m<DBE = 2x - 1 and that m<CBE = 5x - 42.
The sum of angles DBE and CBE = m<DBC = 90°
We can add the two angles and set it equal to 90 to find x

12? im not sure
i think u need to multiply 6 and 2 to get your answer.