Core Connections Algebra 2, 2013
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Core Connections Algebra 2, 2013 View details
1. Section 7.1
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Exercise 111 Page 344

Practice makes perfect
a

We are given the values of log_x2, log_x5, and log_x7. To write log_x10 in terms of the given logarithms, let's first recall three useful Properties of Logarithms.

Properties of Logarithms
Name Product Property Quotient Property Power Property
Condition a>0, b>0, and x ≠ 1 a>0, b>0, and x ≠ 1 m>0, b>0, and b ≠ 1
Property log_x ab = log_x a + log_x b log_x ab=log_x a - log_x b log_b m^p = p log_b m

According to the Product Property, the logarithm of a product is the same as the sum of the logarithms of its factors. Note that 10 is a product of 2 and 5. log_x10=log_x(2* 5) This means we can rewrite the logarithm as a sum. log_x(2* 5)=log_x2+log_x5 Now, we can substitute the given values and find log_x10.

log_x2+log_x5
a+ b

Therefore, log_x10=a+b.

b

Same as in Part A, we will use the Properties of Logarithms. According to the Power Property, the logarithm of a power is the product of the logarithm and the exponent. Note that 49 is a square of 7.

log_x49 = log_x7^2This means we can rewrite the logarithm as product. log_x7^2= 2log_x7 Now we can substitute the given value for log_x7 and find log_x49.

2log_x7
2( c)
2c

Therefore, log_x49=2c.

c

Once again, to find log_x50 we will use the Properties of Logarithms. Before we do that, we should find factors of 50. Since 50 is even, it is divisible by 2.

log_x50=log_x( 2*25) By the Product Property, the logarithm of a product is the same as a sum of the logarithms of its factors. log_x(2*25)=log_x2+log_x25 Now, note that 25 is a square of 5. log_x2+log_x25=log_x2+log_x 5^2 According to the Power Property, we can rewrite the logarithm of a power as a product of the logarithm and the exponent. log_x2+log_x5^2=log_x2+ 2log_x5 Finally, we can substitute the given values.

log_x2+2log_x5
a+2( b)
a+2b

Therefore, log_x50=a+2b.

d

Finally, let's find log_x56. To do so we should first find factors of 56. Note that 56 is divisible by 7.

log_x57=log_x( 7*8) By the Product Property, we can write the logarithm as a sum of logarithms. log_x(7*8)=log_x7+log_x8 Now, note that 8 is a power of 2. log_x7+log_x8=log_x7+log_x 2^3 This allows us to apply the Power Property. log_x7+log_x2^3=log_x7+ 3log_x2 Let's substitute the given values.

log_x7+3log_x2
c+3( a)
c+3a

Therefore, log_x56=3a+c.