a. 18. 22 + 65 : 13=396 + 5=401
b. 135. 32 – 32. 130=32.(135 - 130)=32.5=160
c. 120 – 350 : [26 + (173 – 149)]=120 -350 : (26+24)=120 - 350 : 50=120 - 7=113
d. 17.55 + 43.17 + 12.17=17.(55+43+12)=17.110=1870
e. 20 – [30 – (6 – 1)²]=20 - (30 - 5²)=20 - (30 -25) =20 - 5=15
f. 785 – (323 + 148) : 3 + 2784=785 + 2784 - 471 : 3

=3569 - 157=3412
g. [461 + (-78) + 40] + (-461)=461 - 78 + 40 - 461

=(461 -  461) +(40 - 78)

=0 + (-38)= -38
h. (-87) + (-12) – (-487) + 512

= -87 - 12 + 487 + 512

=(512 -12) + (487 - 87)

=500 + 400=900
i. [53 + (-76)] – [(-76) – (-53)]

=53 - 76 + 76 - 53

=(53 - 53) + (76 - 76)=0
k. -2020 + (-21 + 75 + 2020)

= -2020 - 21 + 75 + 2020

=(2020 - 2020) + (75 - 21)

=0 + 54

=54

a. 18. 22 + 65 : 13

396+5

401

b. 135. 32 – 32. 130

4320-4160

160