Question

Tính 

1) -7129+1478+7129+(-1479)

2) /-5/.(-7)+4.(-9)

3) (-4)²+35:(-7)

Tìm số nguyên x biết 

1) x-9=-5.8

2) x +8=-4+11

3) /x/-2=-3.(-8)

4) /x-2/=/-72/

Answer 1

\(\text{-7129+1478+7129+(-1479)}\)

\(=\text{-7129+7129+1478+(-1479)}\)

\(=0-1=-1\)

Answer 2

\(\text{|-5|.(-7)+4.(-9)}\)

\(=\text{5.(-7)+4.(-9)}\)

\(=\left(-35\right)+\left(-36\right)=-71\)

Answer 3

\(\text{(-4)²+35:(-7)}\)

\(=\text{16+(-5)=11}\)

Answer 4

2. Tìm x

1) x-9=5.8

x-9=40

x=40+9

x=49

2)x+8=(-4)+11

x+8=7

x=7-8

x=(-1)

3)/x/-2=(-3).(-8)

/x/-2=24

/x/=24:2

/x/=12

=>   x=12     hoặc         x=(-12)

4)/x-2/=/-72/

/x-2/=72

=> x-2=72         hoặc        x-2=(-72)

    x  =      72+2                 x=(-72)+2

       x=74                           x=(-70)

      Nếu mk sai thì xin lỗi bn

Answer 5

a)\(\text{ x-9=-5.8}\)

\(\Rightarrow\text{ x-9=-40}\)

\(\Rightarrow x=-40+9=-31\)

b)\(\text{ x +8=-4+11}\)

\(\Rightarrow\text{ x +8=7}\)

c \(\text{|x|-2=-3.(-8)}\)

\(\Rightarrow\left|x\right|-2=24\)

\(\Rightarrow\left|x\right|=26\)

\(\Rightarrow\orbr{\begin{cases}x=26\\x=-26\end{cases}}\)

d)\(\text{|x-2|=|-72|}\)

\(\Rightarrow\left|x-2\right|=72\)

\(\Rightarrow\orbr{\begin{cases}x-2=72\\x-2=-72\end{cases}\Rightarrow\orbr{\begin{cases}x=74\\x=-70\end{cases}}}\)

ttiiik nha