geno3141

40% can be written as  0.40

25.56 - 0.40  =  ????

Use the distributive property:

8a + 6(b - 2a)

=  8a + 6(b) - 6(2a)

=  8a + 6b - 12a

=                                        <---   Finish this to get the answer!

Using the distributive property, multiply them out ---

5(3m + 7n)  =  5(3m) + 5(7n)  =  15m + 35n  <---nope!

Keep doing this until you get the one that works ...

1/4  is  one fourth

    one fourth  is  a quarter

       a quarter  is  25 cents

            25 cents  is  0.25

So,  1/4  is  0.25 ...

or, enter  1/4  into the calculator and press  <ENTER>

Move the decimal point from where it is to immediately after the first digit and count the number of places that you moved it:

Change from  24901.55  to  2.490155 x 10⁴

The exponent '4' is used because the decimal point was moved 4 places to the left.

If the original number is a decimal smaller than 1, you have to move the decimal point to the right, so you make the exponent a negative number.

To find the number of protons given those assumptions, divide the mass of the Earth by the mass of a single proton.

As an order of magnitude estimate, divide 10²⁴ by 10^-27:   10²⁴ / 10^-27  =  10^{24 - -27}  =  10^?

For a more exact answer:    (5.98 x 10²⁴) / (1.67 x 10^-27)  =  (5.98/1.67) x 10^{24 - -27}  =  ?

Exponential growth formula:  A  =  Pe^rt

A = final amount = 53     P = beginning amount = 50     r = rate (as a decimal)    r = time = 10

--->   53  =  50·e^r·10

--->   53  =  50·e^10r

--->   1.06  =  e^10r

--->   ln(1.06)  =  ln(e^10r)

--->   ln(1.06)  =  10r

--->   ln(1.06) / 10  =  r

--->   r  =  0.00583   --->   r  =  0.583%

Population in 2010 (using base year as 1992):  r  =  0.00583  and  t  =  18

--->   A  =  50·e^{0.00583 · 18}

--->   A  =  50·e^0.10494

--->   A  =  55.5 million  

D = r·t

Divide both sides by t:     D/t  =  r     --->     r  =  D/t

D = 120 km  and  t  = 2.5 hr:     r  =  120 km / 2.5 hr  =  48 km/hr

2.07088 x 10²¹

This is found by counting the number of places that you must move the decimal point from the end of the number to the location immediately after the first (left-most) digit.

I'm assuming that the problem is:  y  = 2x² + 5x - 3

This problem can be factored:                (2x - 1)(x + 3)  =  0

                  --->                                       2x - 1  =  0          or          x + 3  =  0

                  --->                                              x  =  1/2       or                 x  =  -3

This problem can also be solved by using the quadratic formula or by completing the square.

By the manner that you asked the question, are you supposed to complete the square?