Answer: 21
Step-by-step explanation: 84/4 = 21
Since l x - 4 l means absolute value, so we need to make sure we do not include any negative signs.
x + 4 = 7 would be the next step because it does not include any negative signs.
Answer:
15 miles in 30 minutes
Step-by-step explanation:
130/2=65 miles per hour
30/2=15
Answer:
The answer is below
Step-by-step explanation:
Show that f(x) f(y) = f(x+y)
From trigonometric:
sin(x + y) = sinxcosy + cosxsiny
sin(x - y) = sinxcosy - cosxsiny
cos(x + y) = cosxcosy - sinxsiny
cos(x - y) = cosxcosy + sinxsiny
![f(x)=\left[\begin{array}{ccc}cosx&-sinx&0\\sinx&cosx&0\\0&0&1\end{array}\right] ,f(y)=\left[\begin{array}{ccc}cosy&-siny&0\\siny&cosy&0\\0&0&1\end{array}\right] \\\\\\f(x)f(y)=\left[\begin{array}{ccc}cosxcosy-sinxsiny&-cosxsiny-sinxcosy&0\\sinxcosy+cosxsiny&-sinxsiny+cosxcosy&0\\0&0&1\end{array}\right] \\\\\\f(x)f(y)=\left[\begin{array}{ccc}cos(x+y)&-sin(x+y)&0\\sin(x+y)&cos(x+y)&0\\0&0&1\end{array}\right] \\\\\\](https://tex.z-dn.net/?f=f%28x%29%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dcosx%26-sinx%260%5C%5Csinx%26cosx%260%5C%5C0%260%261%5Cend%7Barray%7D%5Cright%5D%20%2Cf%28y%29%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dcosy%26-siny%260%5C%5Csiny%26cosy%260%5C%5C0%260%261%5Cend%7Barray%7D%5Cright%5D%20%5C%5C%5C%5C%5C%5Cf%28x%29f%28y%29%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dcosxcosy-sinxsiny%26-cosxsiny-sinxcosy%260%5C%5Csinxcosy%2Bcosxsiny%26-sinxsiny%2Bcosxcosy%260%5C%5C0%260%261%5Cend%7Barray%7D%5Cright%5D%20%5C%5C%5C%5C%5C%5Cf%28x%29f%28y%29%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dcos%28x%2By%29%26-sin%28x%2By%29%260%5C%5Csin%28x%2By%29%26cos%28x%2By%29%260%5C%5C0%260%261%5Cend%7Barray%7D%5Cright%5D%20%5C%5C%5C%5C%5C%5C)
![f(x+y)=\left[\begin{array}{ccc}cos(x+y)&-sin(x+y)&0\\sin(x+y)&cos(x+y)&0\\0&0&1\end{array}\right] \\\\\\Therefore\ f(x)f(y)=f(x+y)](https://tex.z-dn.net/?f=f%28x%2By%29%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dcos%28x%2By%29%26-sin%28x%2By%29%260%5C%5Csin%28x%2By%29%26cos%28x%2By%29%260%5C%5C0%260%261%5Cend%7Barray%7D%5Cright%5D%20%5C%5C%5C%5C%5C%5CTherefore%5C%20f%28x%29f%28y%29%3Df%28x%2By%29)
Answer:
x=1
Step-by-step explanation:
3x - 5 =7x -9
Subtract 3x from each side
3x - 5-3x =7x-3x -9
-5 = 4x-9
Add 9 to each side
-5+9 = 4x-9+9
4 = 4x
Divide each side by 4
4/4 = 4x/4
1=x