A student submitted the following work. Is it correct? If not, what is the mistake? A) The work is correct.

B) The answer is wrong because the student did not distribute correctly.

C) The answer is wrong because the student did not combine like terms correctly.

D) The answer is wrong because the student did not multiply positive and negative numbers correctly.

C) The answer is wrong because the student did not combine like terms correctly.

Step-by-step explanation:

The like terms -9x and +7x come together to make -2x, not +2x

16.9 times 2.85

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