If the mean of data set 7,8,12,3,6 and x is 8 .what is the value of 8

Due to bad planning, two of the local schools have their annual plays on the same weekend. while 457 people attend one, and 372 attend the other, only 104 people were able to attend both. how many people went to at least one play?

What is the equation of the line that is parallel to the line with the equation y= -3/4x +1 and passes through the point (12,-12)

"which statement is necessarily true if bd is an altitude to the hypotenuse of right ? abc? a.) ? adb? ? bdc b.) ? adb~? bdc c.) abbc=acbd d.) ? bac? ? bdc"