-512.
Type negative 8 to the third power in google. It really is the answer. :)
D. Similar SSS similarity triangle TLM
2.
0.05 miles
3.
a
4.
a
5.
1 Book for ever 10$
6.
28 MPH
Thats it!
Hope this helps
So the equation looks like this : 15*3x=78
subtract 15 from both sides: -15 -15
then divide by 3 from both sides
to isolate the variable: 3x=63
3/3x=63/3
x=21 (your mystery number is 21)