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# Alg 2 Questions

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1. What are the x and y-intercepts of the equation?

y=log(7x+3)−2

Round the answers to the nearest hundredth.

x-intercept =

y-intercept =

2. What is the exact value of x?

5⋅215x=16

These are the options:

x=log3.25log21

x=log215log3.2

x=5log3.2log21

x=5log21log3.2

3.

What is the exponential form of the logarithmic equation?

5=log0.90.59049

I really appreciate the help, thanks so much!

Dec 24, 2017

#1
+2

Here is another post with two of the same questions on it:

http://web2.0calc.com/questions/what-is-the-exact-value-of-x-urgent-help

1.     y  =  log(7x + 3) - 2

To find the x-intercept, plug in  0  for  y  and solve for  x .

0  =  log(7x + 3) - 2     Add  2  to both sides of the equation.

2  =  log(7x + 3)          Exponentiate both sides with a base of  10 .

102  =  10log(7x + 3)

100  =  7x + 3             Subtract  3  from both sides.

97  =  7x                     Divide both sides by  7 .

97/7  =  x

the x-intercept   =   97/7   ≈  13.86

To find the  y-intercept, plug in  0  for  x  and solve for  y .

y  =  log(7(0) + 3) - 2         Simplify.

y  =  log(3) - 2                   Plug this into a calculator to get...

y  ≈  -1.52

the y-intercept   ≈   -1.52

Dec 24, 2017
#2
+2

2.     I am guessing that your equation is this...

5⋅215x  =  16

Divide both sides of the equation by  5 .

215x  =  3.2

Take the log of both sides.

log( 215x )  =  log( 3.2 )

Now we can bring the  x  out like this...

x log 215   =   log 3.2

Divide both sides by  log 215  .

x  =  log 3.2 / log 215       Your answer options look a bit mixed up...

Dec 24, 2017
edited by hectictar  Dec 24, 2017
#3
+2

3.

5  =  log 0.9059049

105  =  0.9059049

Dec 24, 2017