Answer:
Multiplication
Step-by-step explanation:
I think what you're talking about is not a decimal, but a multiplication point:

This dot can donate multiplication when in the middle of two numbers and/or fractions.
But if you're talking about some other point, then I don't know, sorry. :(
Answer: 24
Step-by-step explanation:
Answer:
r=28.27 cm aprox
Step-by-step explanation:
Well you know that the area of a circle is A= 
so
2511=
so
=2511/
r=28.27 cm aprox
15 miles cause you do 5 times 3 and you get 15 miles
(9x+5) - (6x-8) = 9x+5 - 6x+8 = (9x-6x) + (5+8) = 3x+13
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(4x+10) - (-3x+5) = 4x+10 + 3x-5 = (4x+3x) + (10-5) = 7x+5