Let i = sqrt(-1) which is the conventional notation to set up an imaginary number
The idea is to break up the radicand, aka stuff under the square root, to simplify
sqrt(-8) = sqrt(-1*4*2)
sqrt(-8) = sqrt(-1)*sqrt(4)*sqrt(2)
sqrt(-8) = i*2*sqrt(2)
sqrt(-8) = 2i*sqrt(2)
<h3>Answer is choice A</h3>
Answer:
78.54
Step-by-step explanation:
first you have to divided 31.4 by 3.14 to get your diameter so you can get your radius. 31.4 divided by 3.14 equals 10 and 10 divided by 2 equals 5 which is you radius. The formula for area for a circle is πr². 5 squared is 25 and 3.14 times 25 equals 78 .54 which is your answer.
The sign only changes when divided or multiplied by a negative number.
Simplifying
5x + 2(8x + -9) = 3(x + 4) + -5(2x + 7)
Reorder the terms:
5x + 2(-9 + 8x) = 3(x + 4) + -5(2x + 7)
5x + (-9 * 2 + 8x * 2) = 3(x + 4) + -5(2x + 7)
5x + (-18 + 16x) = 3(x + 4) + -5(2x + 7)
Reorder the terms:
-18 + 5x + 16x = 3(x + 4) + -5(2x + 7)
Combine like terms: 5x + 16x = 21x
-18 + 21x = 3(x + 4) + -5(2x + 7)
Reorder the terms:
-18 + 21x = 3(4 + x) + -5(2x + 7)
-18 + 21x = (4 * 3 + x * 3) + -5(2x + 7)
-18 + 21x = (12 + 3x) + -5(2x + 7)
Reorder the terms:
-18 + 21x = 12 + 3x + -5(7 + 2x)
-18 + 21x = 12 + 3x + (7 * -5 + 2x * -5)
-18 + 21x = 12 + 3x + (-35 + -10x)
Reorder the terms:
-18 + 21x = 12 + -35 + 3x + -10x
Combine like terms: 12 + -35 = -23
-18 + 21x = -23 + 3x + -10x
Combine like terms: 3x + -10x = -7x
-18 + 21x = -23 + -7x
Solving
-18 + 21x = -23 + -7x
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '7x' to each side of the equation.
-18 + 21x + 7x = -23 + -7x + 7x
Combine like terms: 21x + 7x = 28x
-18 + 28x = -23 + -7x + 7x
Combine like terms: -7x + 7x = 0
-18 + 28x = -23 + 0
-18 + 28x = -23
Add '18' to each side of the equation.
-18 + 18 + 28x = -23 + 18
Combine like terms: -18 + 18 = 0
0 + 28x = -23 + 18
28x = -23 + 18
Combine like terms: -23 + 18 = -5
28x = -5
Divide each side by '28'.
x = -0.1785714286
Simplifying
x = -0.1785714286
Answer:
- y = 81-x
- the domain of P(x) is [0, 81]
- P is maximized at (x, y) = (54, 27)
Step-by-step explanation:
<u>Given</u>
- x plus y equals 81
- x and y are non-negative
<u>Find</u>
- P equals x squared y is maximized
<u>Solution</u>
a. Solve x plus y equals 81 for y.
y equals 81 minus x
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b. Substitute the result from part a into the equation P equals x squared y for the variable that is to be maximized.
P equals x squared left parenthesis 81 minus x right parenthesis
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c. Find the domain of the function P found in part b.
left bracket 0 comma 81 right bracket
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d. Find dP/dx. Solve the equation dP/dx = 0.
P = 81x² -x³
dP/dx = 162x -3x² = 3x(54 -x) = 0
The zero product rule tells us the solutions to this equation are x=0 and x=54, the values of x that make the factors be zero. x=0 is an extraneous solution for this problem so ...
P is maximized at (x, y) = (54, 27).