Hi there.
To start, we have to understand where the ten the place is.
Hint: it's 1 place behind the decimal point.
Now we need to know what numbers behind the tenths place make it round up or down.
If the number behind it is 4 or under, round down.
5 & up, round up.
In this case, 830.248 has 2 numbers behind the decimal, so we have to round those THEN the 2 in the tenths place.
830.25 to 830.3
Your answer is D. 830.3
I know this was lengthy, sorry. Just wanted to explain :p
Answer:
Volume = 1539.38 cm³
Surface Area = 747.7 cm²
Step-by-step explanation:
Volume = πr² h
V = π(7)²(10)
V = π(49)(10)
V = 490π
V = 1539.38 cm³
Surface Area = 2πrh + 2πr²
SA = 2π(7)(10) + 2π(7)²
SA = 2π(70) + 2π(49)
SA = 140π + 98π
SA = 238π
SA = 747.7 cm²
SOLUTION:
Let whole number = x
x + 2x^2 = 21
2x^2 + x - 21 = 0
2x^2 + 7x - 6x - 21 = 0
x ( 2x + 7 ) - 3 ( 2x + 7 ) = 0
( 2x + 7 ) ( x - 3 ) = 0
2x + 7 = 0
2x = - 7
x = - 7 / 2
OR
x - 3 = 0
x = 3
ANSWER:
Therefore, as 3 is a whole number while - 7 / 2 isn't a whole number, the whole number must be 3.
Hope this helps! :)
Have a lovely day! <3
