Step-by-step explanation:
A) [-3+(6-8)] - [40+(5.3-7)+20.2]
= [-3+(-2)] - [40+(-1.7)+20.2]
= [-3-2] - [40-1.7+20.2]
= [-5] - [38.3+20.2]
= [-5] - [58.5]
= -5 - 58.5
= -63.5
B) -4+[-2.6-1-(-3.4)]+(-5).(-3)+(-10)]
= -4+[-3.6+3.4]+(-15)+(-10)
= -4+[-0.2]-15-10
= -4+[-0.2]-25.
= -4-0.2-25
= -4.2-25
= -29.2
C) -22{-5+[8.3-(3.6-9)]}-(-2)(3)
= -22{-5+[8.3-(-5.4)]}-(-2)(3)
= -22{-5+[8.3+5.4]}-(-2)(3)
= -22{-5+13.7}-(-6)
= -22{8.7}+6
= -191.4+6
= -185.4
D) -9-(-2+5).[-3+(-5)-(+2)+1]
= -9-(3)[-3+(-5)-(+2)+1]
= -9-3[-3+(-5)-(+2)+1]
= -12[-3+(-5)-(+2)+1]
= -12[-3-5-2+1]
= -12[-10+1]
= -12[-9]
= 108.
E) 40{-12[4+(-6)(-5)-15.3+12]}-2
= 40{-12[4+(-30)-15.3+12]}-2
= 40{-12[4-30-15.3+12]}-2
= 40{-12[-26-15.3+12]}-2
= 40{-12[-29.3]}-2
= 40{-12-29.3}-2
= 40{-41.3}-2
= 1652-2
= 1650.
F) -21{-[-6(7-3)]-(7.6-8.3)}-89
= -21{-[-6(4)]-(7.6-8.3)}-89
= -21{-[-24]-(7.6-8.3)}-89
= -21{24-(-0.7)}-89
= -21{24+0.7}-89
= -21{24.7}-89
= -518.7-89
= -607.7