Melody

$$\\\frac{x}{-7}>-4\\\\
x<-4*-7$$

when you mult or divide by a neg number you have to turn the inequality sign around. :)

What about it?

the value of sin has to be between -1 and 1 so it cannot equal -12/5

(-1/2)(4x)(-2)(7y)(-1)=

=(-1/2)(4)(-2)(7)(-1)xy

=-2*-2*7*-1xy

=4*7*-1xy

=-28xy

or

4/4+8 = 1+8=9        Since there are no brackets this is how it should be done.:)

We are glad that you like it 

By definition

$$i=\sqrt{-1}$$

Remember this is not a real number it is an imaginary number!

squares and square roots cancle each other out so

$$\\i^2=(\sqrt{-1})^2 = -1\\\\
i^4=i^2\times i^2=-1\times-1=+1\\\\
i^6=i^4\times i^2=1\times-1=-1\\\\
i^8=i^6\times i^2=-1\times-1=+1\\\\
i^{10}=i^8\times i^2=+1\times-1=-1\\\\$$

does that help you to understand?  

$$-6c^2 + 3c^2=-3c^2$$

C=2*pi*r

=2*3.14*2.5 metres

If you do this on a calculator you will need to put the times sign between the  pairs of brackets.

(-4.13)*(-0.8)