Answer:
x = -1 ± √109
Step-by-step explanation:
2x • 3x + (2 • 3)x + 6x = 648
According to PEMDAS (parentheses/exponents | multiplication/division | addition/subtraction), we should solve the parentheses first.
(2 • 3) = 6
Now we have:
2x • 3x + (6)x + 6x = 648
Now let's multiply.
2x • 3x = 6x²
6 • x = 6x
Now we have.
6x² + 6x + 6x = 648
Combine like terms.
6x² + 12x = 648
Let's factor out a 6.
6(x² + 2x) = 648
Divide both sides by 6.
x² + 2x = 108
Let's use completing the square.
Our equation is in a² + bx = c form.
Divide b by 2.
2/2 = 1
Then square it.
1² = 1
Add 1 to both sides.
x² + 2x + 1 = 108 + 1
Simplify.
x² + 2x + 1 = 109
Now we want to factor the left side. A shortcut is just to use b/2.
(x + 1)² = 109
Take the square root of both sides.
x + 1 = ±√109
The square root is as simplified as possible.
Subtract 1 from both sides.
x = -1 ± √109
Hope this helps!
Well 1/40 is 0.025 so that should be the write fraction to use
Answer:
A dictionary has the mass of about 1 killo so the book!
Step-by-step explanation:
Answer:
You will put 1220.83ft³ of water in the pool
Step-by-step explanation:
First of all we have to calculate the volume of the pool and then calculate 80% of that volume
radius = half of diameter
d = 18ft
r = 18ft / 2 = 9ft
To calculate the volume of a cylinder we have to use the following formula:
v = volume
h = height = 6ft
π = 3.14
r = radius = 9ft
v = (π * r²) * h
we replace with the known values
v = (3.14 * (9ft)²) * 6ft
v = (3.14 * 81ft²) * 6ft
v = 254.34ft² * 6ft
v = 1526.04ft³
The volume of the cylinder is 1526.04ft³
If it is filled to 80% then we have to multiply the volume by 80/100
1526.04ft³ * 80/100 = 1220.83ft³
You will put 1220.83ft³ of water in the pool
