Which statement about x in equation a-x=2a is true
a. x is equal to twice a
b. x must be greater than a
c. x must be equal to the opposite of a
d. x does not have any real number values

C. X would be equal to -a so if we consider the absolute positive value ( module) X would be a

yes because they have the same amount of green and blur marbles.

step-by-step explanation:

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4