There are many ways to solve simultaneous linear equations. One of my favorite for finding integer solutions is graphing. The attached graph shows the solution to be ...
... (x, y) = (4, 7)
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You can also use Cramer's Rule, or the Vedic math variation of it, which tells you the solution to

is given by

Here, that means
... x = (9·67-5·75)/(9·8-5·3) = 228/57 = 4
... y = (75·8-67·3)/57 = 399/57 = 7
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A (graphing) calculator greatly facilitates either of these approaches.
7 people, 7 walls, 48 minutes
Each person paints 1 wall in 48 minutes
20 persons, 20 walls
Each can paint 1 wall in 48 minutes so it will
take 48 minutes.
1 cup per 8 oz
48/6 = 8
every 1 cup of water 8 oz of tomato paste.
Answer:

Step-by-step explanation:
Given
--- rate of hard disk drives failure
--- number of hard disk drives
<em>See comment for complete question</em>
Required

First, calculate the probability that the none of the 4 selected is working;



Using the complement rule, the probability that at least 1 is working is:

This gives:


Answer:
M(5,2)
Step-by-step explanation:
We use the midpoint rule:

We just have to find the arithmetic mean of the x and y-coordinates.
The endpoints of CD are given as C(3,−5) and D(7, 9).
We substitute these values to get:



Therefore the coordinates of the midpoint M of CD are (5,2)