Simply you can substitute theta=45 degrees (or any angle,not zero) in left hand side and right hand side.
or
using a^2 - b^2 =(a+b)(a-b)
= sin(2x+x)sin(2x-x)
= sin 3x sin x
The answer for the first box is 90
Why? Because this is from the expression 90x+1500. The 90x means the slope is 90. So each time x goes up by 1, the value of y goes up by 90
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The answer to the second box is 1500
If you were to plug in x = 0, then
y = 90x+1500
y = 90*0+1500
y = 1500
So he earns $1500 for selling 0 copies
First off you need to convert the numbers into mixed numbers.
1 3/7 goes to 10/7
3 2/3 goes to 11/3
Then you multiply the numerators together:
10 * 11 = 110
Do the same for the denominators:
3 * 7 = 21
Then place it into a fraction and you make the fraction positive because the signs at the start are the same:
110/21
Then you can turn it into a proper fraction:
5 5/21
