In ordered pair below, which value represents the output of a function? (1, 9)

9

Step-by-step explanation:

In the notation of a function f(x) = x+8, for input x=1 the output would be 9. And (1,9) would be an (x,y) pair that fits the function.

what?

step-by-step explanation:

what do you need with. i love quadrants. can you tell me ?

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