X+ 9 = 18 + -2x
how do you solve this? and what is the answer? i forgot how to. (11th grade) you.

"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"

The box plots show the distributions of the numbers of words per line in an essay printed in two different fonts.which measure of center would be best to compare the data sets? the median is the best measure because both distributions are left-skewed.the mean is the best measure because both distributions are left-skewed.the median is the best measure because both distributions are symmetric.the mean is the best measure because both distributions are symmetric

Ablue whale traveled 3112 miles in 214hours. what was the whale's rate in yards per hour? (1 mile = 1,760 yards)