Answer:
10
Step-by-step explanation:
(2/3) x (15)
is the same as
(2/3) x (15/1)
which means after you multiply them you get:
30/3
which simplifies to:
10
<h2>angle in triangle</h2>
because the triangle above is an isosceles triangle, then both angles are of the same value.
and one thing you should know, the angle above shows the straight angle.
<em>so the sum of all angles is 180</em><em>°</em>
<u>can be written like </u><u>this</u><u> </u><u>:</u>
(5x+13)°+(3x+7)°=180°
5x + 13 + 3x + 7 = 180
8x + 20 = 180
8x = 180 - 20
8x = 160
x = 20
<em>(*the third choice is correct)</em>
you do them at the end, if it's only 9+10 then just add them.

multiplecation is first, then addition. meaning the answer is 26