math help 2 questions?

5x-3[7-2(6x-7)-3x]

Want to know the steps to reach the conclusion the answer: 50x-63


(2-5i)/(3+4i)

I think i is -1 what method do I use is it foil?

answer: (-14/25)-(23/25i)

Como2013-01-30T02:27:27Z

Favorite Answer

1.
5x - 3 [ 7 - 12x + 14 - 3x ]
5x - 3 [ 21 - 15x ]
50 x - 63

2.
(2 - 5i)(3 - 4i)
-----------------
(3 + 4i)(3 - 4i)

6 - 23i - 20
---------------
9 + 16

-14 - 23i
------------
25

(-14/25) - (23/25) i

Pranil2013-01-30T06:56:19Z

5x - 3[7 - 2(6x - 7) - 3x]
= 5x - 3[7 - 12x + 14 - 3x]
= 5x - 3[21 - 15x]
= 5x - 63 + 45x
= 50x – 63

(2 - 5i)/(3 + 4i)
= (2 - 5i)(3 – 4i)/(3 – 4i)(3 + 4i)
= (6 - 22i – 20)/(9 + 16)
= (– 14 – 22i)/( 25)
= (– 14/25) – (22i)/( 25)
----