Answer:
x=-x+2i
x=-x-2i
Step-by-step explanation:
Step-by-step explanation:
1.Read the Entire Word Problem.
2.Think About the Word Problem.
3.Write on the Word Problem.
4.Draw a Simple Picture and Label It.
5.Estimate the Answer Before Solving.
6.Check Your Work When Done.
7.Practice Word Problems Often.
Answer:
(d) 30 units²
Step-by-step explanation:
The area of the rectangle is the product of the length and width. It is equal to the number of unit squares that fill the rectangle.
__
By counting grid squares or subtracting coordinates, we can see this rectangle is 3 units wide and 10 units high. Its area will be ...
A = WH
A = (3 units)(10 units) = 30 units²
_____
<em>Additional comment</em>
You can also count the three columns of 10 shaded squares, or the 10 rows of 3 shaded squares. Either way, you will count 30 square units covering the rectangle.
Perimeter (p) = 2×length (l) + 2×width (w)
p = 2l+2w
area (a) = l×w, so solve for one (I'll use l):
since p = 30, and a = 50, substitute the "a÷w" in for l in the perimeter equation:
Now plug in p and a values:
therefore width can be either 5 or 10 (but not both), so let's plug in:
l = a÷w = 50÷5 = 10
So if w = 5, then l = 10
D) 5 feet, and 10 feet
Answer:
268 mg
Step-by-step explanation:
Let A₀ = the original amount of caffeine
The amount remaining after one half-life is ½A₀.
After two half-lives, the amount remaining is ½ ×½A₀ = (½)²A₀.
After three half-lives, the amount remaining is ½ ×(½)²A₀ = (½)³A₀.
We can write a general formula for the amount remaining:
A =A₀(½)ⁿ
where n is the number of half-lives
.
n = t/t_½
Data:
A₀ = 800 mg
t₁ = 10 a.m.
t₂ = 7 p.m.
t_½ = 5.7 h
Calculations:
(a) Calculate t
t = t₂ - t₁ = 7 p.m. - 10 a.m. = 19:00 - 10:00 = 9:00 = 9.00 h
(b) Calculate n
n = 9.00/5.7 = 1.58
(b) Calculate A
A = 800 × (½)^1.58 = 800 × 0.334 = 268 mg
You will still have 268 mg of caffeine in your body at 10 p.m.
