If the sum is negative or if the signs are different and the negative has a biger absoulute value.
2(5*10)+2(10*4)+2(5*4)=
2(50)+2(40)+2(20)=100+80+40=
220 cm^2
I found the answer by finding the areas of the 3 different sides, multiplying each area by 2 since each side has another side that is equal on a rectangular prism, then adding all of them together.
<em><u>Question:</u></em>
Hector has a floor plan showing his new house. On the floor plan, his bedroom is 3 inches wide and 3 1/2 inches long. The scale of the floor plan is 1/4 inch = 1 foot. What is the actual length of Hector’s room?
<em><u>Answer:</u></em>
The actual length of Hector room is 14 foot
<em><u>Solution:</u></em>
Given that, On the floor plan, his bedroom is 3 inches wide and
inches long
<em><u>The scale of floor plan is given as:</u></em>

Therefore,

To find: Actual length of floor
From given question,

Converting the mixed fraction to improper fraction,

Since, 1 inch = 4 foot

Thus actual length of Hector room is 14 foot
From the second:
2x-y=4
x=(4+y)/2 and applying this to first:
4+y+3y=12
4y+4=12
4y=8
y=2 and since x=(4+y)/2, x=3 so
x+y=2+3=5
Using the normal distribution, it is found that 25.14% of the batteries will last more than 420 hours.
<h3>Normal Probability Distribution</h3>
The z-score of a measure X of a normally distributed variable with mean
and standard deviation
is given by:

- The z-score measures how many standard deviations the measure is above or below the mean.
- Looking at the z-score table, the p-value associated with this z-score is found, which is the percentile of X.
In this problem, we have that the mean and the standard deviation are given, respectively, by:
.
The proportion of the batteries will last more than 420 hours is <u>one subtracted by the p-value of Z when X = 420</u>, hence:


Z = 0.67
Z = 0.67 has a p-value of 0.7486.
1 - 0.7486 = 0.2514.
0.2514 = 25.14% of the batteries will last more than 420 hours.
More can be learned about the normal distribution at brainly.com/question/24663213
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