In △abc, m∈ ac and n∈ bc . prove that mn ∥ ab , if: cm/ma= cn/nb

See explanation

Step-by-step explanation:

In triangle △ABC, M∈ AC and N∈ BC and

then

and

Consider triangles ABC and MNC. In these triangles,

Hence, by SAS similarity theorem. Similar triangle have congruent corresponding angles, so

Angles ABC and MNC are corresponding angles when lines AB and MN are cut by transversal BC. Since these angles are congruent, by converse of  corresponding angles theorem, lines AB and MN are parallel.

the answer is 99.

the 8 in 8,420 is in the thousands place so it's value is 8 thousand.

the 8 in 6,870 is in the hundreds place so it's value is 8 hundred.

divide 8000 by 800 to find the answer:

8000 / 800 = 10

the 8 in 8,420 is 10 times greater than the 8 in 6,870