Core Connections Algebra 1, 2013
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Core Connections Algebra 1, 2013 View details
2. Section 1.2
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Exercise 37 Page 20

Practice makes perfect
a Before we sketch the next two figures of the given tile pattern, let's consider the differences between the existing figures.

Look at the figures, we can notice that there is a clear pattern. Each figure has 5 more tiles on the right side than the previous figure. Each time, the bottom and top of the figure are 2 tiles longer, and the middle is 1 tile longer. Therefore, Figure 4 would have 8 tiles on its top and bottom, and 5 tiles in the middle.

Figure0 will have 5 tiles less than the Figure 1. That means this figure will be made from one tile.

b Let's call the number of an arbitrary figure x and the number of tiles in that figure y. From the information in the exercise, we can measure the change in x and y between Figure 1 and Figure 2.
Since the pattern grows at a constant rate, we know that the equation is linear. y=mx+b From the table, we see that the rate of change between Figure 1 and Figure 2 increases by 5 which can be translated into a slope of 5. y=5x+b To finalize the equation, we also need to find the y-intercept b. We can do that by substituting either of the known points, (1,6) or (2,11), into the equation and solving for b.
y=5x+b
6=5( 1)+b
â–Ľ
Solve for b
6=5+b
1=b
b=1
Substituting both of the known values into the equation, we have y=5x+1. By substituting x=10 into the equation, we can calculate the number of tiles that will be in figure 10.
y=5x+1
y=5( 10)+1
y=50+1
y=51
There are 51 tiles in Figure 10.