MaxWong

72x72+75x75

=10809

This is sooooo long. I will divide it into 2 parts.

First part 

= $10(\frac{1+i}{1-i})^8$

=$10(\frac{1^2+2i-1}{1-(-1)})^8$

= $10(i)^8$

=$10$

Second part

=$5(\frac{1+i}{1-i})^6$

=$5i^6$

= $-5$

First part - Second part 

= 10 - (-5)

=15

What is (b)?

Can you state it more clearly?

x²+x-2 = (x+2)(x-1)

(3x+1)(x²+x-2)

= 3x³+4x²-5x-2

Therefore a = 3 b = 5

btw the hint is no use xD

20 x 7 x 17 x 8 x 3 x 15 =140 x 17 x 8 x 3 x 5 = 2380 x 8 x 3 x 5 = 19040 x 3 x 5 = 57120 x 5 = 285600

There are only 3 factors of 25. which is 1, 5, and 25 and there are only 2 ways to get 25

1x 25 = 25 Sum: 1+25 = 26

5x 5 = 25 Sum: 5+5 = 10

5 and 5 will produce the lowest sum

$\frac{540 000+33000}{2}$

=$\frac{573000}{2}=286500$

What do you mean by negative log

logarithm of negative number can never be calculated

instead -log(number) can be calculated.

just input -log(number)?

1.3*77^7

= 1.3*16048523266853

=20863080246908.9 

sin²π/3 + tanπ/3

= $(\frac{\sqrt{3}}{2})^2+\sqrt 3$

=$\frac{3}{4}+\sqrt{3}$

= $\frac{3+4\sqrt3}{4}$