Answer:
600
Step-by-step explanation:
31 plus 29 is 60
60 x 10 = 600
Answer:

The number is 8 because 
And if you add 4, you get 20
Hence, the number is 8
Answer: Not 100% sure but this is what I think.
-4/5
Step-by-step explanation:
(5, -1) (15, −9)
1Y - 2Y / 1X - 2X = SLOPE
-1 + 9 / 5 - 15 = 8/-10 = -8/10 = -4/5
X² - 10x = 46
10/2 = 5; 5²+ 25 add 25 to both sides
x² - 10x + 25 = 46 + 25
so the number you have to add to complete the square is 25.