0,4(3)+0,6(2)*2 1/2 - 1/2+1/3 / 0,5(8):50/53

Объяснение:

0,4(3)+0,6(2)*2 1/2 - 1/2+1/3 / 0,5(8):50/53=

39/90+56/90 *2,5-  (1/2+1/3)/(53/50 : 50/53)=

39/90+140/90-  (5/6)/(53/90 *53/90)=

=39/90+14/9)-(5/6)/(2809:4500)=

=(39+140)/90-5/6 *4500/2809=   179/90- 3750/2809=

=(502811 -337500)/252810=165311/252810≈0,65

*0,4(3)=39/90

*0,6(2)=56/90

*0,5(8)=53/90

1.а)(4х+3)(4х-3)=16х-9

б)(3х-2)^2=9х^2-12x+4

в)(x+5)(x^2-5x+25)=(x+5)(x-5)^2=x^2-25*(x-5)

2. a)x^3-9x=x(x^2-9)=x(x+3)(x-3)

b)-5^2-10ab-5b^2=-5(a^2+2ab+b^2)=-5(a+b)^2

c)25x^2-y^2=(5x-y)(5x+y)