Math Questions With Answers (3)

A set of math questions related to exponential and logarithmic expressions and equations are presented. The answers are provided and are located at the lower part of the page.

Questions 1:

Evaluate the given exponential expressions without using a calculator.

A. 1040.5

B. 10log(9) / 2

C. e3 ln(4)

D. 10-2 Log(4)

E. e2 Ln(4) - ln(16)

Questions 2:

Evaluate the following logarithmic expressions without using a calculator.

A. Log9(3)

B. Log2(1/8)

C. Log2(400) - Log2(100)

D. Log8(4)

E. Log5(600) - Log5(24)

Questions 3:

Solve the following exponential equations.

A. ex = 4

B. ex = Pi 2

C. 4log4(3x - 2) = 10

D. 10log10(3x) = 15

E. 3x+1 + 3x + 3x-1 = 39

Questions 4:

Solve the following logarithmic equations.

A. ln(ln(x)) = 4

B. ln(x) - ln(4) = 2 ln(x) - ln(16)

C. (ln(x))5 = 255/2

D. Log(x - 1) = Log(6) - Log(x)

E. Log3(3x+1 - 18) = 2

F. Log7(x) + Logx(7) = 2

G. Logx(27) = 3/4

ANSWERS TO ABOVE QUESTIONS

Answers to Questions 1:

A. 1040.5 = 104 * 0.5 = 102 = 100

B. 10log(9) / 2 = 10log(91/2) = 3

C. e3 ln(4) = e ln(43) = 43 = 64

D. 10-2 Log(4) = 10Log(4-2) = 4-2 = 1/16

E. e2 Ln(4) - ln(16) = eLn(42) - ln(16) = e0 = 1

Answers to Questions 2:

A. Log9(3) = Log9(91/2) = 1/2

B. Log2(1/8) = Log2(2-3) = -3

C. Log2(400) - Log2(100) = Log2(400/100) = 2

D. Log8(4) = Log8(82/3) = 2/3

E. Log5(600) - Log5(24) = Log5(600/24) = Log5(25) = 2

Answers to Questions 3:

A. x = ln(4)

B. x = 2 ln(Pi)

C. 3x - 2 = 10 , x = 4

D. 3x = 15 , x = 5

E. Multiply all terms of the equation by 3 to obtain

3x+2 + 3x+1 + 3x = 39 *3

Factor 3x out: 3x(9 + 3 + 1) = 39 * 3

Simplify : 3x = 9 and solve: x = 2

Answers to Questions 4:

A. Solve for ln(x): ln(x) = e4 , solve for x: x = ee4

B. rewrite equation: ln(x/4) = ln(x2/16) , gives: x/4 = x2/16 , solve for x: x = 4

C. rewrite equation: (ln(x))5 = 55 , gives: ln(x) = 5 , solve for x: x = e5

D. Rewrite as: Log(x - 1) = Log(6/x) ,
gives: x - 1 = 6/x, solve for x and check: x = 3 is the only solution.

E. Rewrite without Log: 3x+1 - 18 = 32, solve for x: x = 2

F. Use change of base formula to rewrite equation:
ln(7) / ln(x) + ln(x) / ln(7) = 2
rewrite as: (ln(7))2 + (ln(x))2 - 2ln(7) ln(x) = 0
( ln(7) - ln(x) )2 = 0 , which gives: ln(7) = ln(x)
solve for x: x = 7

G. Rewrite without Log: x3/4 = 27 , solve for x: x = 34

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