If you had the number 4 1/4 you would divide the numerator (1) by the denominator (4) and then take the decimal number (0.25) you get and add the decimal to the whole number on your mixed number (4+0.25) and that would give you the decimal.
Answer:
The cost of hardbook is $9 and cost of paperback is $5.
Step-by-step explanation:
Let x be the price for hardback book and y be the price for paperback book.
Mr. Yamamoto purchased 42 new hardcover books and 64 new paperback books, which cost a total of $698.
We can write the equation as:

He also purchased 42 new hardcover books and 58 new paperback books, which cost a total of $668.
We can write the equation as:

We have to use the elimination method to solve the two equations.
We eliminate x by subtracting the two equations.

Thus, the cost of hardbook is $9 and cost of paperback is $5.
Answer:
Possible
Step-by-step explanation:
First make it that both denominators are the same.

Then add both numerators

Your final answer should be
Step-by-step explanation:
I am not sure what you want to calculate as ultimate goal.
but your have an error already in your third line in the picture.
(3-6i)(2-4i) = 3×(2-4i) - 6i(2-4i)
you had there a "+" instead of a "-".
and then you made subsequent mistakes in every line, some of them are funnily bringing you more back to the real result (e.g. -12i + 12i would be 0 and not -24i, but if the third line would have been correct, then yes, -24i is actually needed) - but not completely.
= 3×2 - 3×4i - 6i×2 + 6i×4i =
= 6 - 12i - 12i + 24×-1 = 6 - 24i - 24 = -24i - 18
then in the last 3 lines you kind of lose it completely. I am absolutely not sure, what you are calculating, and where the "+" cube from instead of "×" (multiplications) and such.
(3+6i)(2+4i) = 3×2 + 3×4i + 6i×2 + 6i×4i =
= 6 + 12i + 12i + 24×-1 =
= 6 + 24i - 24 = 24i - 18
is that what you wanted to show ?