Recall that
sin(<em>a</em> + <em>b</em>) = sin(<em>a</em>) cos(<em>b</em>) + cos(<em>a</em>) sin(<em>b</em>)
sin(<em>a</em> - <em>b</em>) = sin(<em>a</em>) cos(<em>b</em>) - cos(<em>a</em>) sin(<em>b</em>)
Adding these together gives
sin(<em>a</em> + <em>b</em>) + sin(<em>a</em> - <em>b</em>) = 2 sin(<em>a</em>) cos(<em>b</em>)
To get 14 cos(39<em>x</em>) sin(19<em>x</em>) on the right side, multiply both sides by 7 and replace <em>a</em> = 19<em>x</em> and <em>b</em> = 39<em>x</em> :
7 (sin(19<em>x</em> + 39<em>x</em>) + sin(19<em>x</em> - 39<em>x</em>)) = 14 cos(39<em>x</em>) sin(19<em>x</em>)
7 (sin(58<em>x</em>) + sin(-20<em>x</em>)) = 14 cos(39<em>x</em>) sin(19<em>x</em>)
7 (sin(58<em>x</em>) - sin(20<em>x</em>)) = 14 cos(39<em>x</em>) sin(19<em>x</em>)
So first I would say, what if all of them were dimes, how far away would it be from $14?
So 92 coins * 10 cents = $9.20
So it's 4.80 dollars away from 14 dollars.
So if we were to switch one to a quarter, it would increase by 0.15 cents.
So we want to see how many increases we need to reach 4.80 dollars more.
4.80/0.15 = 32
So there are 32 quarters and 60 dimes.
Answer:
Step-by-step explanation:
There is no list and no choices given.
The solutions of | x | = 10 are x = 10 and x = -10 .
All (both) solutions happen to be integers.
There are no other solutions.
So first do 3(x+1) which is 3x+3 because you have to multiply the outside number by the stuff in side the parentheses. Then you do the 5(x-2)+7 and it should be 5x-10+7 so now your equation should be 3x+3=5x-10+7 now subtract the 3x from the 5x and now your equation should look like this: 3=2x-10+7. Then you add the 10 and the 7 so now your equation should look like this: 3=2x-3 because it's a -10 and a positive 7 it would be -3. So then you have to add the -3( which now becomes positive to the other 3 in front of the = sign. So now your equation should look like this: 6=2x. Now divide by 2 to get x by its self and now your answer should be 3=x or x=3.
