geno3141

You are correct!

Answer book can be incorrect (even though that's rare).

Did you copy the problem correctly?

Are you looking at the right answer in the answers?

2.9 cu ft x 30  =  87 cu ft

Is there a complication that you didn't include in the question?

 I suggest using a calculator, possibly the one at this site.

It depends upon where the side is compared to where the angle is:

If the side is opposite the angle (across the triangle from the angle) then use sin:  sin(A) = a / hyp                    where you know the values for the angle A and the opposite side a.

If the side is adjacent to the angle (next to it), then cos:  cos(A) = b /                                                             w;here you know the values for the angle A and the adjacent side b.

You can use the Pythagorean Theorem:  c² = a² + b²

If a = 230 and b = 410, then you need to solve  c² = 230² + 410².       Can you finish this?

(You could make a = 410 and b = 230; you would get the same answer.)

       so     Since s = 3  -->        3o         Since m can't be 3,   -->     3o

+many                              +many         m must be 2 and          +2any

--------                              --------         there must be a           --------

  sums                                 3um3         carry.                            3u23

Now since o + y = 3, either o = 2 and y =1  or  o = 1 and y = 2 (both impossible because n = 2)                       -->    o = 6 and y = 7  or o = 7 and y = 6   (so their sum ends with a 3)

Try  o = 6 and y = 7   -->     36                3 + n + 1 (a carry) has a sum that ends with 2;

                                       2an7                 the sum must be 12 and n must be 8

                                    --------

                                       3u23

-->        36      -->  Now, a + 1 (a carry) must add to u; but this sum has to be at least 10, so there

       + 2a87              is a carry for the next columns to the left:  therefore, the sum is exactly 10,

        -------              so u = 0.  This forces a to be 9.

         3u23

              36

        + 2987

        --------

            3023              But, this is the answer when o = 6 and y = 7; could y = 6 and o = 7?

Is your question:  How do you divide faction that are written in scientific notation?

Basically, divide the numbers, and subtract the exponents:

Examples:

   (2.3 x 10^8) ÷ (5.6 x 10^3)  =  (2.3 ÷ 5.6) x (10^8 ÷ 10^3)  =  0.42 x 10^5  =  4.2 x 10^4

   (3.5 x 10^7) ÷ (1.7 x 10^-4)  =  (3.5 ÷ 1.7) x (10^7 ÷ 10^-4)  =  2.1 x 10^11

   (1.5 x 10^-8) ÷ (7.5 x 10^-9)  =  (1.5 ÷ 7.5) x (10^-8 ÷ 10^-9)  =  0.2 x 10^1  =  2

Remember:  divide the numbers; subtract the exponents.

What is the question?

If you need to factor the expression:  2x² - xy  =  x(2x - y)

Additive Inverse Property

sin²θ(1 + cot²θ)  =  1

Since 1 + cot²θ = csc²θ:

sin²θ·csc²θ  =  1