Đáp án:
Giải thích các bước giải:
c1: -45; -38 ;(-2)3;(-1)4; 0; 13; |-15|;29; 33;
c2:a, -30.6 - 10. (12 - 18)=-3.10.6-10.12+10.18
=-18.10-10.12+10.18=-10.12=-120
b) 23.(-57) + 57.(-87) – 20 . 57
=-57(23+87+20)=-57.130=-7410
c) 25.(32 + 47) - 32(25 + 47)
=25.32+25.47-32.25-32.47
=47(25-32)=-7.47=-329
d) 1+2-3-4+5+6-7-8+....-99-100+101+102-103-104+105+106
=(1+106)+(2+105)-.....+(53+54)=53+54=107
c3: a) x – (-2) = 32 + (-19)
⇔x=11
b) 2x – 30 = x + 49
⇔x=79
c) 2|x + 8| = -4 + 6
⇔|x+8|=1 ⇔ \(\left[ \begin{array}{l}x+8=1\\x+8=-1\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=-7\\x=-9\end{array} \right.\)
c4: a, pt⇔ x(y+3)-7(y+3)=0
⇔(x-7)(y+3)=0
⇔$\left \{ {{y=-3} \atop {x=7}} \right.$