Lacey, because you have to do the opposite when you want to get rid of a number. She subtracted 20 because it was originally positive 20. Chris messed up and did not do the opposite, subtraction, and instead he added 20
There is a trig identity called the sum of 2 angles for sin its<span>
sin(a+b)=sin(a)cos(b)+cos(a)(sin(b)
</span>
You will need to use it. So in your question split the 4x in 2 equal parts 2x and 2x
<span>
</span><span>sin(4x)=sin(2x+2x)
</span>Now using the expansion above you will get
<span>sin(2x+2x)=sin(2x)×cos(2x)+cos(2x)×sin(2x)
</span>And it will simplify to
<span><span>2sin(2x)cos(2x)
I hope this helps you! Good luck :)</span></span>
Answer:
8/45
Step-by-step explanation:
Define x to be the value of your fraction:
____
When in doubt, you can use your calculator to see which fraction gives you 0.1777777778.
_____
We multiplied by 10^1 above, because there is 1 repeating digit. The power of 10 we use matches the number of repeating digits.
So you subtitute y=3x into
2x+y=15
so
2x+(3x)=15
add like terms
5x=15
divide both sides by 5
x=3
subtitute x=3 into first equation (y=3x)
y=3(3)
y=9
$16 is the answer
Maybe I’m actually not sure
