Algebra II : Exponents

Study concepts, example questions & explanations for Algebra II

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Example Questions

Example Question #75 : Solving Exponential Equations

Solve for \displaystyle x.

\displaystyle 7^{x+5}=7^{12}

Possible Answers:

\displaystyle 7

\displaystyle 13

\displaystyle 6

\displaystyle 17

\displaystyle 8

Correct answer:

\displaystyle 7

Explanation:

When dealing with exponential equations, we want to make sure the bases are the same. This way we can set-up an equation with the exponents.

\displaystyle 7^{x+5}=7^{12} With the same base, we can now write

\displaystyle x+5=12 Subtract \displaystyle 5 on both sides.

\displaystyle x=7

Example Question #76 : Solving Exponential Equations

Solve for \displaystyle x.

\displaystyle 12^{x+4}=12^{8}

Possible Answers:

\displaystyle 6

\displaystyle 8

\displaystyle 4

\displaystyle 12

\displaystyle 2

Correct answer:

\displaystyle 4

Explanation:

When dealing with exponential equations, we want to make sure the bases are the same. This way we can set-up an equation with the exponents.

\displaystyle 12^{x+4}=12^{8} With the same base, we can now write

\displaystyle x+4=8 Subtract \displaystyle 4 on both sides.

\displaystyle x=4

Example Question #77 : Solving Exponential Equations

Solve for \displaystyle x.

\displaystyle 14^{x+16}=14^{-13}

Possible Answers:

\displaystyle 3

\displaystyle 14

\displaystyle 19

\displaystyle -3

\displaystyle -29

Correct answer:

\displaystyle -29

Explanation:

When dealing with exponential equations, we want to make sure the bases are the same. This way we can set-up an equation with the exponents.

\displaystyle 14^{x+16}=14^{-13} With the same base, we can now write

\displaystyle x+16=-13 Subtract \displaystyle 16 on both sides.

\displaystyle x=-29

Example Question #78 : Solving Exponential Equations

Solve for \displaystyle x.

\displaystyle 12^{2x+17}=12^{-13}

Possible Answers:

\displaystyle 12

\displaystyle -13

\displaystyle 11

\displaystyle -15

\displaystyle 14

Correct answer:

\displaystyle -15

Explanation:

When dealing with exponential equations, we want to make sure the bases are the same. This way we can set-up an equation with the exponents.

\displaystyle 12^{2x+17}=12^{-13} With the same base, we can now write

\displaystyle 2x+17=-13 Subtract \displaystyle 17 on both sides.

\displaystyle 2x=-30 Divide \displaystyle 2 on both sides.

\displaystyle x=-15

Example Question #79 : Solving Exponential Equations

Solve for \displaystyle x.

\displaystyle 2^{3x+8}=4

Possible Answers:

\displaystyle -6

\displaystyle 5

\displaystyle 1

\displaystyle -2

\displaystyle 3

Correct answer:

\displaystyle -2

Explanation:

When dealing with exponential equations, we want to make sure the bases are the same. This way we can set-up an equation with the exponents. Since the bases are now different, we need to convert so we have the same base. We do know that

\displaystyle 4=2^2 therefore

\displaystyle 2^{3x+8}=2^2 With the same base, we can now write

\displaystyle 3x+8=2 Subtract \displaystyle 8 on both sides.

\displaystyle 3x=-6 Divide \displaystyle 3 on both sides.

\displaystyle x=-2

Example Question #80 : Solving Exponential Equations

Solve for \displaystyle x.

\displaystyle 3^{3x-6}=27

Possible Answers:

\displaystyle 6

\displaystyle 3

\displaystyle 5

\displaystyle 2

\displaystyle 4

Correct answer:

\displaystyle 3

Explanation:

When dealing with exponential equations, we want to make sure the bases are the same. This way we can set-up an equation with the exponents. Since the bases are now different, we need to convert so we have the same base. We do know that

\displaystyle 27=3^3 therefore

\displaystyle 3^{3x-6}=3^3 With the same base, we can now write

\displaystyle 3x-6=3 Add \displaystyle 6 on both sides.

\displaystyle 3x=9 Divide \displaystyle 3 on both sides.

\displaystyle x=3

Example Question #81 : Solving And Graphing Exponential Equations

Solve for \displaystyle x.

\displaystyle 4^{2x-7}=64

Possible Answers:

\displaystyle 10

\displaystyle 7

\displaystyle 9

\displaystyle 3

\displaystyle 5

Correct answer:

\displaystyle 5

Explanation:

When dealing with exponential equations, we want to make sure the bases are the same. This way we can set-up an equation with the exponents. Since the bases are now different, we need to convert so we have the same base. We do know that

\displaystyle 64=4^3 therefore

\displaystyle 4^{2x-7}=4^3 With the same base, we can now write

\displaystyle 2x-7=3 Add \displaystyle 7 on both sides.

\displaystyle 2x=10 Divide \displaystyle 2 on both sides.

\displaystyle x=5

Example Question #82 : Solving And Graphing Exponential Equations

Solve for \displaystyle x.

\displaystyle 7^{4x+8}=1

Possible Answers:

\displaystyle 1

\displaystyle -2

\displaystyle 3

\displaystyle -1

\displaystyle 0

Correct answer:

\displaystyle -2

Explanation:

When dealing with exponential equations, we want to make sure the bases are the same. This way we can set-up an equation with the exponents. Since the bases are now different, we need to convert so we have the same base. We do know that

\displaystyle 7^0=1 therefore

\displaystyle 7^{4x+8}=7^0 With the same base, we can now write

\displaystyle 4x+8=0 Subtract \displaystyle 8 on both sides.

\displaystyle 4x=-8 Divide \displaystyle 4 on both sides.

\displaystyle x=-2

Example Question #83 : Solving And Graphing Exponential Equations

Solve for \displaystyle x.

\displaystyle 4^{2x+5}=8^{x}

Possible Answers:

\displaystyle 12

\displaystyle -5

\displaystyle 7

\displaystyle -9

\displaystyle -10

Correct answer:

\displaystyle -10

Explanation:

When dealing with exponential equations, we want to make sure the bases are the same. This way we can set-up an equation with the exponents. Since the bases are now different, we need to convert so we have the same base. We do know that

\displaystyle 4=2^2, 8=2^3 therefore

\displaystyle (2^2)^{2x+5}=(2^3)^{x} Apply power rule of exponents.

\displaystyle 2^{4x+10}=2^{3x} With the same base, we can now write

\displaystyle 4x+10=3x Subtract \displaystyle 4x on both sides.

\displaystyle 10=-x Divide \displaystyle -1 on both sides.

\displaystyle -10=x

Example Question #91 : Solving And Graphing Exponential Equations

Solve for \displaystyle x.

\displaystyle 25^{x+1}=125^{x+4}

Possible Answers:

\displaystyle 9

\displaystyle 11

\displaystyle -5

\displaystyle -10

\displaystyle -8

Correct answer:

\displaystyle -10

Explanation:

When dealing with exponential equations, we want to make sure the bases are the same. This way we can set-up an equation with the exponents. Since the bases are now different, we need to convert so we have the same base. We do know that

\displaystyle 25=5^2, 125=5^3 therefore

\displaystyle (5^2)^{x+1}=(5^3)^{x+4} Apply power rule of exponents.

\displaystyle 5^{2x+2}=5^{3x+12} With the same base, we can now write

\displaystyle 2x+2=3x+12 Subtract \displaystyle 2x, 12 on both sides.

\displaystyle x=-10

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