Answer:
Step-by-step explanation:
Step 1: Equation at the end of step 1
Simplifying
60(x + 20) = 3x
Reorder the terms:
60(20 + x) = 3x
(20 * 60 + x * 60) = 3x
(1200 + 60x) = 3x
Solving
1200 + 60x = 3x
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-3x' to each side of the equation.
1200 + 60x + -3x = 3x + -3x
Combine like terms: 60x + -3x = 57x
1200 + 57x = 3x + -3x
Combine like terms: 3x + -3x = 0
1200 + 57x = 0
Add '-1200' to each side of the equation.
1200 + -1200 + 57x = 0 + -1200
Combine like terms: 1200 + -1200 = 0
0 + 57x = 0 + -1200
57x = 0 + -1200
Combine like terms: 0 + -1200 = -1200
57x = -1200
Divide each side by '57'.
x = -21.05263158
Simplifying
x = -21.05263158
Think of 10^2, 10^1, and 10^0 as x^2, x^1, and x^0.
When you add polynomials, you can only combine like terms.
When you add expanded numbers, you can only combine like powers of 10.
123 + 423 =
= (100 + 20 + 3) + (400 + 20 + 3)
= (1 * 10^2 + 2 * 10^1 + 3 * 10^0) + (4 * 10^2 + 2 * 10^1 + 3 * 10^0)
= (1 * 10^2 + 4 * 10^2) + (2 * 10^1 + 2 * 10^1) + (3 * 10^0 + 3 * 10^0)
= 5 * 10^2 + 4 * 10^1 + 6 * 10^0
= 500 + 40 + 6
= 546
The answer is 4 7/9.
Since you cannot subtract the numerators, you have to take 1 from the whole number, so 9 turns into 8 and you add the denominator to the numerator to make the equation 8 15/9 - 4 8/9 which is 4 7/9 :).
Answer: 6
Step-by-step explanation: 9 times 2/3 =6
area equals length times width
Answer:
B. 87
Step-by-step explanation:
The first thing is to calculate critical z factor
the alpha and the critical z score for a confidence level of 90% is calculated as follows:
two sided alpha = (100% - 98%) / 200 = 0.01
critical z factor for two sided alpha of .01 is calculated as follows:
critical z factor = z factor for (1 - .01) = z factor for (.99) which through the attached graph becomes:
critical z factor = 2.33
Now we have the following formula:
ME = z * (sd / sqrt (N) ^ (1/2))
where ME is the margin of error and is equal to 75, sd is the standard deviation which is 300 and the value of z is 2.33
N the sample size and we want to know it, replacing:
75 = 2.33 * (300 / (N) ^ (1/2))
solving for N we have:
N = (2.33 * 300/75) ^ 2
N = 86.86
Which means that the sample size was 87.
