What is the solution of (x+8)/(5x+-1)>0?

the solution set is (-infinity, -8) ∪ (-8, 1/5)

Step-by-step explanation:

x + 8 changes sign at x = -8.  

I'll assume you meant 5x - 1 (as 5x+- is meaningless).  5x - 1 changes sign at x = 1/5.

Subdivide the x-axis using the two x-values found above:

(negative infinity, -8), (-8, 1/5), (1/5, infinity.

Choose a representative value from each interval.  I'm choosing x = -10, x = 0 and x = 1.

Now test the given inequality at each of these x-values.  Is the result true or false?

 x + 8

> 0

5x - 1

For x = -10:

-10 + 8

> 0 => -2/(-51) => 2/51     This is TRUE

5(-10) - 1

For x = 1:

 1 + 8

> 0  =>  9/4     This is TRUE

  5 - 1

For x = 0:

     8

> 0    This is FALSE

    - 1

Therefore the solution set is (-infinity, -8) ∪ (-8, 1/5)

i dont know sorry

step-by-step explanation:

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.