19. 5x - 5 = 3x -9
2x = -4
x = -2
19. Answer is A
it means the distance around a two dimensional shape.
To find the perimeter, add all the side lengths
hope it helps!!!!!!!
The correct answer is 10,000
The segment marked 20 is the geometric mean of the two pieces into which it splits the hypotenuse. You get the proportion

Solving,

To find b, use the fact that b is the geometric mean of the whole hypotenuse, 21 + a, and the part that is attached to it, a.

A little arithmetic shows that

.