Question

giúp mik với ạ

Answer 1

BÀi 1:

a: (-31)+(-17)=-(31+17)=-48

b: 29-43=-(43-29)=-14

c: (-15):5=-15:5=-3

d: (-27):(-9)=27:9=3

e: \(\left(-15\right)\cdot7=-\left(15\cdot7\right)=-105\)

f: (-31)-19=-(31+19)=-50

g: (-115)-(-15)+100

=-115+15+100

=-115+115

=0

h: \(\left(-5\right)\cdot\left(-7\right)+65:13\)

=35+5

=40

k: \(407-\left\lbrack\left(190-170\right):4+9\right\rbrack\)

=407-[20:4+9]

=407-(5+9)

=407-14

=393

Dạng 2:

a: 156-(x+61)=82

=>x+61=156-82=74

=>x=74-61

=>x=13

b: (x-35)-120=0

=>x-35-120=0

=>x-155=0

=>x=155

c: 124+(118-x)=217

=>124+118-x=217

=>242-x=217

=>x=242-217

=>x=25

d: 7x-8=713

=>7x=8+713=721

=>\(x=\frac{721}{7}=103\)

e: \(x-36:18=-2\)

=>x-2=-2

=>x=-2+2

=>x=0

f: (x-36):18=-2

=>\(x-36=-2\cdot18=-36\)

=>x=-36+36

=>x=0

g: \(23+3x=5^6:5^3\)

=>\(3x+23=5^3=125\)

=>3x=125-23=102

=>x=102/3=34

h: 484+x=-632+(-548)

=>x+484=-632-548=-1180

=>x=-1180-484

=>x=-1664