Solve logarithm equation please with steps.

Answers

Answer 1

Answer: The first time I did it, I got an answer that's not one of the choices. The second time
I did it, I got an answer that IS . Here are both of my procedures. If all you want is
the answer, look down below at the second one. But if you could help me out, now
that you know how to do this stuff, please look at my first solution and tell me where
I messed up. I can't find it.
=======================================================

Here's what the problem tells you:

D = 10 log ( ' I ' / 10⁻¹² )

D = 60 . . . . . find ' I ' .

Here we go:

60 = 10 log ( ' I ' / 10⁻¹² )

Divide each side by 10 :

6 = log ( ' I ' / 10⁻¹² )

Raise 10 to the power of each side of the equation:

10⁶ = ' I ' / 10⁻¹²

Multiply each side by 10¹² :

10¹⁸ = ' I '     That's 10^18. It looks bad, because that isn't one of the choices.

Let's try a slightly different procedure:

============================================

After substituting 10⁺¹² for I₀ , we're working with this formula:

   D = 10 log ( 'I' / 10⁺¹² )

Let's just look at the log part of that.

The log of a fraction is [ log(numerator) - log(denominator) ]

log of this fraction is [ log( 'I' ) - log(10⁻¹²) ]

But log(10⁻¹²) is just (-12) .

So the log of the fraction is [ log( 'I' ) + 12 ]

And the whole formula is now:

   D = 10 [ log( 'I' ) + 12 ]

60 = 10 [ log( 'I' ) + 12 ]

Divide each side by 10 :

6 = log( 'I' ) + 12

Subtract 12 from each side :

-6 = log ( ' I ' )

' I ' = 10⁻⁶

That's choice-'B' .

==================================================

I'm going to leave the first solution up there, in hopes that you, or one
of the many aces, experts, and geniuses that prowl this site constantly,
can weigh in and show me my blunder on the first attempt.

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A tree casts a 25 foot shadow. At the same time of day, a 6 foot man standing near the tree casts a 9 foot shadow. What is the approximate height of the tree to the nearest foot? A) 16 feet
B) 17 feet
C) 18 feet
D) 19 feet

Answers

Answer:

Answer is option b

17 feet.

Step-by-step explanation:

Given that A tree casts a 25 foot shadow. At the same time of day, a 6 foot man standing near the tree casts a 9 foot shadow.

for man actual height = 6 foot

Shadow = 9 foot

At a particular time, the height/shadow ratio would be constant

Hence 6/9 =x/25

Or x = 25(6)/9

x=16.67feet

Rounding off x=17 feet

ratio of object to shadow = 6/9 = x/25 (where x is the height of the tree)
x = (6 * 25)/9 = 16.67feet

x = approx. 17 feet

The lengths of the sides of a rectangular window have the ratio 1.6 to 1. The area of the window is 2,560 square inches. What are the dimensions of the window? A. 50.6 inches by 50.6 inches
B. 40 inches by 64 inches
C. 40 inches by 80 inches
D. 40 inches by 102.4 inches

Answers

S = a*b this is formula for surface.
Condition of the task is:
a:b = 1.6:1
a = 1.6*b

Now we implement this in surface formula
S = 1.6*b^2
and calculate "b"

$b= \sqrt{ (S)/(1.6) }$

b = 40
a = 1.6*40 = 64

Answer is B.

I think it is B you need to divide

3 and a Half cubes of sand transported at once. How many times do vehicle travel to transport 28 sand cubes.

Answers

Answer:

8 times

Step-by-step explanation:

28/3.5 = 8

4) What is the slope of the line graphed by the equation y = (-⅓)x - 3?(A) (-1/3)
(B) -3
(C) (1/3)
(D) 3

Answers

SImple,

this line is in the form of y=mx+b..which means that m=slope and b=y-intercept..

Thus, the slope for this line is.... $-(1)/(3)$

Thus, your answer, A.

y=mx+b
m=slope
y=-1/3x-3

m=-1/3
slope=-1/3

answer is A

Pwease help its just easy math