Krystal used a number line to add. She started counting at 10, and then she counted until she was on the number −4 on the number line. What number did she add to 10?

6

Step-by-step explanation:

BECAUSE YOU ACT LIKE IF IT IS THE SAME AND THEN YOU SUBTRACT AS IF THEY ARE POSITIVE THEN YOU KEPP THAT NEGATIVE AND THEN YOU GET 6

first, you divide the triangle in two, tô form a retangle triangle. after, using pythagoream theorem:

18^2 = 14^2 + (x/2)^2

(x^2/4) + 196 = 324

x^2/4 = 324 - 196

x^2/4 = 128

x^2 = 512

x = √512

x = √2^9

x = 16√2 cm

i hope i you.