a) thay -34 vao x ta co :
-34+234=200
b) thay 25 vao x ta co (dang x sao a ?)
25+125=150
c) thay -17 vao a va -15 vao b ta co
-17x2+15+15
=-34+30
=-4
d) thay -34 vao x ta co :
576+34= 610
e) thay -120 vao z ta co :
(-209) + (-120) +109
=-329 + 109
=-220