Please help me with this. 10 points. thank you.

7.639 times 10^6

Step-by-step explanation:

You move the decimal all the way until you get a number between 1 and 10. Then you count the digits behind where you would place the decimal (7.639) and that would be your exponent. Finally, place it in scientific notation from to get 7.639 times 10^6

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