= 6/5a3x 4/(3/5ax 3)-0.9 ax3/(3/5ax 3)

=2 a2x-3/2

(4) (7x2y3-8x3y2z)/ 8x2y2

=7x2y3/ 8x2y2 - 8x3y2z/ 8x2y2

= 7/8y–xz

(5) 12 13/(3 10*4 1 1)

=(3*4) 13 /3 10 /4 1 1

=(3 13 /3 10) *(4 13 /4 1 1)

=33*42

=27* 16=432

(6) (54*33-53*32+52*3)/ 15

=5*3(53*32-52*3+5)/ 15

=53*32-52*3+5= 1055

6(x+y)2 = x2+y2+2xy = 25(x-y)2 = x2+y2-2xy = 9

The two formulas add x2+y2=(25+9)/2= 17.

Subtract xy=(25-9)/4=4.