MaxWong

You mean a² ?

$a^2 \mbox{ is equivalent to } a \times a$

Oops sorry forget to choose LaTeX

$-7-(-2)\\ = -7+2\\ = 2 -7 \\ = -5\\ \therefore\text{-7-(-2) is -5}$

-7-(-2)\\

= -7+2\\

= 2 -7 \\

= -5\\

\therefore\text{-7-(-2) is -5}

No, I think he is a liar. He wrote that he have found the answer to his own problem but until now no mathematicians have found that answer........

Try typing ' 2^4 = ' on the calculator. 

It will show $\mathtt{2^4=16}$

$2\cos(90)-\sec(90)\\ =2(1)-\frac{1}{\cos(90)}\\ =2(1)-\frac{1}{1}\\ = 2- 1\\ =1$

$\text{My align looks bad. I am going to make it look better.}\\ \begin{align*}2x&-5y&=&\quad8\\3x&+9y&=&\;-12\end{align*}$

Add up the 2 equations.....

10x = 24

x = 2.4

Substitute the value......

5(2.4)+4y = 2

4y = 2 - 12 = -10

y = -2.5

My mom is not on this forum though XD haven't even registered but she does have great maths skills.

Perimeter of triangle = 16 + 3x + 4x - 3 = 7x + 13

Perimeter of square = Perimeter of triangle = 7x + 13

Each side of square = 7/4 x + 13/4