What is the value of x? The image is of a triangle with a base marked as 21. The other two sides are 10 and 17. Altitude from the top vertex to the base is marked as ALTCxALTC.

A. 6
B. 7
C. 8
D. 9

i pretty sure it is

9 x 8 divided by (5-3)=36

6mm^3 or .6cm^3

      216

      /   \

  36     6

  /   \     /

6     6   6

factor trees are nice.

x² + 3x + 7 = 0       [ax² + bx + c]

a = 1

b = 3

c = 7

quadratic formula:

    (+/- is this ±)

plug in the numbers into the variables

your answer is a