a) -3 ² + { -54 : [(-2) ³ + 7 . 2] . (-2) ²}
=-9+[-54:(-8+14).4]
=-9+(-54:6.4)
=-9-34
=-43
b) - ( 2789 - 435 ) + ( 1789 - 435 )
= -2789+435+1789-435
=-1000
c) - ( -2010) + 36 . 41 - 36 . (-59) + (-2010)
=2010+36.41-36.(-59)+(-2010)
=36.41-36.(-59)+(2010-2010)
=36.41-36.(-59)
=36.[41-(-59)]
=36.(41+59)
=36.100
=3600
d) -75 . (18 - 65) - 65 . (75 - 18)
=3525-3705
=-180
Bài 2
a) 2 . (x - 3) - 3 . (x - 5) = 4 . (3 - x) - 18
2x-6-3x+15=12-4x-18
-x+9=8x-18
-x+9-8x+18=0
(=)-9x+27=0
(=)-9x=-27
(=)x=-27:(-9)
(=)x=3
b)-2x - 11 chia hết cho 3x + 2
=) -3(-2x-11) chia hết cho 3x+2
=) 6x+33 chia hết cho 3x+2
=)(6x+4)+29 chia hết cho 3x+2
=)2(3x+2) +29 chia hết cho 3x+2
=) 29 chia hết cho 3x+2
=)3x+2 ∈Ư(29)=(±1;±29)
1)3x+2=-29=)3x=-31=)x=$\frac{-31}{3}$
2)3x+2=-1=)3x=-3=)x=-1
3)3x+2=1=)3x=-1=)x=-$\frac{1}{3}$
4)3x+2=29=)3x=27=)x=9