Ireally suck at math! could someone me with this questio?

it is  p(a)+p(b)-p(a∩b)

=2/3 + 1/5

=13/15

(c)

Step-by-step explanation:

you could have look this up on soup calculator it might give better explanation and is what i use to use when i didn't understand something

34

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