Help quickly explanation needed. lots of points.

29.3

Step-by-step explanation:

to find average you find the sum of all the minutes she practiced and divide it by the total amount of day she practiced.

first we have to find the sum of the minutes she practiced:

20+30+40+38+25+22+39+22+26+31

this equation is equal to 293 minutes she practiced in total. Now we have to divide this by the total amount of days she practiced whice according to the data is 10! So:

293/10 =29.3

true

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