Simplify the expressions Write the results using only positi
Solution
3(a) t5/t3 = t5*t-3 = t5-3 = t2 ( as 1/an= a-n and am *an= am+n)
(b) (3x3y)4 = 34(x3)4y4 = 81x3*4y4= = 81x12y4 ( as (ab)n= anbn and (am)n= amn).
(c) (a2b-3)2/a3b2 = a2*2 b-3*2/ a3b2 = a4*a-3/b6*b2= a4-3/b6+2 = a/b8 ( as x-n= 1/xn).
(d) (x3y2)(xy3)= (x3*x)(y2 *y3 )= x3+1y2+3 = x4y5.
4.(a) (4)-3/2 = (22)-3/2 = 22*(-3/2) = 2-3 = ½3 = 1/8.
(b) (8x3y2)1/3 = (23x3y2)1/3 = (23)1/3(x3)1/3 (y2)1/3= 23*1/3 x3*1/3y2*1/3 = 2xy2/3.
(c ) (9y3/z2) = (32y3/z2)1/2 = (32)1/2(y3)1/2/(z2)1/2= 32*1/2y3*1/2/z2*1/2 = 3y3/2/z ( as (a/b)n= an/bn).
(d) 82 -38 = 82 -3(4*2) = 82 -322*2 = 82 -3*22 = 82 -62 = 22 = 2*21/2 = 23/2.
5. 3/(x-2) = 3(x+2)/ (x-2) (x+2) = 3(x+2)/[(x)2-(2)2]= 3(x+2)/(x-2) ( as (a+b)(a-b) = a2 –b2).
6. (a)(6+5i)-(3-i) = 6-3+5i+i = 3+6i.
(b) (5-8i)2 = 52-2*5*8i +(8i)2 = 25-80i +82i2 =25-80i -64i = -39-80i ( as (a-b)2 = a2-2ab+b2 and i2 = -1).
(c) (3+8i)/(1+3i) = (3+8i)(1-3i)/(1+3i)(1-3i) = ( 3+8i-9i-24i2)/[12-(3i)2] = ( 27-i)/10 = (27/10)-i/10 ( as i2=-1).
