Laws Of Exponents Flashcards
a small number that is written on the upper right of another number (or variable) which is called the base
Exponent
Example 1:Compute 35
Solution:The exponent of 5 tells us that 3 is multiplied by itself five times.
Therefore, 35= 243
Example 1:What is the value of -94?
Solution:-94is an example of Case 1. To compute for -94, we need to calculate 94first. Afterward, multiply the result by -1:
6561
Example 2:What is the value of (- 9)4?
Solution:Since – 9 is inside the parentheses, it indicates that – 9 is what is being raised to the power of 4. Thus, we need to multiply – 9 to itself four times.
6561
Example 1:Write k5in expanded form.
Solution:The exponent in k5tells us that the variable k is being multiplied by itself 5 times. Thus, the expanded form of k5is:
k5= k∙k∙k∙k∙k
Example 2:Expressu∙u∙u∙u∙u∙u in exponential form.
Solution:Note that the variableuis used six times. Hence, we must use an exponent of 6. Thus:
u∙u∙u∙u∙u∙u= u6
Example 1:Write -3x5in expanded form.
Solution:The variablexis the only one raised to the power of 5. Thus, only the variablexis the base of exponent 5 in the given, and -3 is not included.
Thus, -3x5= -3(x∙x∙x∙x∙x)
Example 2:Write (-3x)5in expanded form.
Solution:The existence of the parentheses indicates that both the -3 and x in -3xare raised to the power of 5. Thus, -3x is the base of exponent 5.
In other words, (-3x)5= -3x∙–3x∙ -3x∙–3x∙ -3x
Suppose we want to multiplyx2byx4. Note thatx2andx4have the same base.How can we multiply them?
One possible method is to expandx2andx4:
x2= x∙x
x4= x∙x∙x∙x
Multiplying the expanded values:
x2∙x4 (x∙x)∙( x∙x∙x∙x)
Note that we can express the product of the expanded values into exponential form:
(x∙x)∙( x∙x∙x∙x) =x∙x∙x∙x∙x∙x =x6
Therefore,x2∙x4=x6
Example 1:Compute for 2⁴∙2²
Solution:We have expressions with the same bases (i.e., 2) being multiplied together. Thus, we can apply the product rule.
Let us copy the common base first:
Then, add the exponents:
Thus, using the product rule:2⁴∙2²= 2⁶
Example 2:Multiply b⁵by b³
Solution:Since we have the same bases being multiplied together, we can apply the product rule:
Let us copy the common base first:
Then, add the exponents:
Therefore, using the product rule:b⁵∙b³=b⁸
Example 3:Multiply a³b²by a²b⁴
Solution:We have two bases involved here, the variablesaandb.
Thus, we need to apply the product rule, each foraandb:
Let us copy the common bases first:
Add the exponents for the common bases.
Hence,a³b²∙a²b⁴=a⁵b⁶
Example 4:Multiply (x + 5)⁶by (x + 5)³
Solution:In this case, the common base isx + 5.Hence, we can apply the product rule.
Let us copy the common base first:
Add the exponents:
Therefore,(x + 5)⁶∙(x + 5)³= (x + 5)⁹
Example 5:Compute for a(a²)
Solution: If two variables are written together with the other one enclosed in parentheses, it implies that the variables are being multiplied. Since we have a common base in the given (which isa), we can apply the product rule here.
Note that if a number or a variable has no exponent written above it, it implies that the exponent is 1.
Let us copy the common base first:
Add the exponents:
Therefore,a(a²) = a³
Example 1:Compute for x⁷÷x³
Solution:Since we are dividing exponential expressions with the same base, we can apply the quotient rule.
Let us copy the common base first:
Subtract the exponents:
Therefore,x⁷÷x³= x⁴
Example 2:Simplify x⁹⁄x⁴
Solution:x9⁄x4also means x9÷ x4. Since we are dividing exponential expressions with the same base, we can apply the quotient rule.
Let us start by copying the common base:
Finally, subtract the exponents:
Therefore, x⁹/x⁴= x⁵
Example 3:Simplify p⁸q²⁄p⁶q
Solution:We have two bases involved: the variablespandq. Thus, we will use the quotient rule for the variablespandq.
Copying the common bases:
Finally, subtract the exponents for each of the common bases.
Hence,p8q2⁄p6q= p²q
Example 4:Divide 1 000 000 000 by 1 000 000
Solution:Note that we can express1 000 000 000 as 109. On the other hand, we can express 1 000 000 as 106. Therefore, we can answer the problem by dividing 109by 106.
Since we have a common base (which is 10), we can apply the quotient rule:
Let us copy the common base first:
Then, subtract the exponents:
Therefore, the answer is 103or 1000.
Tip:We can express a multiple of 10 into exponential form quickly by counting the number of zeros it has. For example, 1 000 000 000 has 9 zeros. Thus, if we express 1 000 000 000 in exponential form, we can determine the exponent to be used based on the number of zeros it has. Therefore 1 000 000 000 = 10⁹
Example 1:Simplify (k⁴)²
Solution:Notice that the entirek4is raised to 2. Applying the power rule, we can combine the exponents into one by multiplying them. Thus,
(k4)2= k4×2= k8
Therefore,(k4)2= k⁸
Example 2:What is the value of (32)3?
Solution:Applying the product rule:
(32)3= 32×3= 36
Now, all we need to do next is expand 36:
3 ∙ 3 ∙ 3 ∙ 3 ∙ 3 ∙ 3 = 729
Therefore,(32)3= 729