a, 2^3 .5-3^3.4+4.6
= 8.5-27.4+4.6
= (8.5)-(27.4)+(4.6)
= 40-108+24
=-44
b,100/{250/[450-(4.5^3-2^2.25)]}
=100/{250/[450-(4.45-4.25)]}
=100/{250/[450-(4.45)-(4.25)
= 100/{250/[450-180-100]
=100/{250/170}
=100/1,47
=68,02
c,|(-5)+(-3)|.3-40
= |-8|.3-40
=8.3-40
= 24-40
=-16