mk mới lp 6

\(\left|a\right|=1,5\Rightarrow\orbr{\begin{cases}a=1,5\\a=-1,5\end{cases}}\)

\(Th1:a=1,5;b=-0,75\)hay \(a=\frac{3}{2};b=\frac{-3}{4}\)

\(\Rightarrow M=\frac{3}{2}+2.\frac{3}{2}.\frac{-3}{4}-\frac{-3}{4}\)

\(=\frac{6}{4}+\frac{-9}{4}+\frac{3}{4}=0\)

\(Th2:a=-1,5;b=0,75\)hay \(a=\frac{-3}{2};b=\frac{-3}{4}\)

​\(\Rightarrow M=\frac{-3}{2}+2.\frac{-3}{2}.\frac{-3}{4}-\frac{-3}{4}\)​

\(=\frac{-6}{4}+\frac{9}{4}+\frac{3}{4}=\frac{3}{2}\)

1=13500

2=103500

Xét 2 trường hợp

TH1: a = -1,5

Ta có \(B=\dfrac{-1,5}{2}-\dfrac{2}{-0,75}\)\(=\dfrac{23}{12}\)

TH2: a = 1,5

Ta có \(B=\dfrac{1,5}{2}-\dfrac{2}{-0,75}=\dfrac{41}{12}\)

bạn xài cái này gõ công thức ra đi

a) \(A=\left[\dfrac{x+2}{x^2-x}+\dfrac{x-2}{x^2+x}\right].\dfrac{x^2-1}{x^2-x}\)

\(A=\left[\dfrac{x+2}{x\left(x-1\right)}+\dfrac{x-2}{x\left(x+1\right)}\right].\dfrac{x^2-1}{x^2+2}\)

\(A=\left[\dfrac{\left(x+2\right)\left(x+1\right)+\left(x-2\right)\left(x-1\right)}{x\left(x-1\right)\left(x+1\right)}\right].\dfrac{x^2-1}{x^2+2}\)

\(A=\left[\dfrac{x^2+2x+x+2+x^2-2x-x+2}{x\left(x-1\right)\left(x+1\right)}\right].\dfrac{x^2-1}{x^2+2}\)

\(A=\dfrac{2x^2+4}{x\left(x^2-1\right)}.\dfrac{x^2-1}{x^2+2}\)

\(A=\dfrac{2\left(x^2+2\right)\left(x^2-1\right)}{x\left(x^2-1\right)\left(x^2+2\right)}=\dfrac{2}{x}\)

b) Thay \(x=-200\) vào biểu thức \(A=\dfrac{2}{x}\) ta được :

\(A=\dfrac{2}{x}=\dfrac{2}{-200}=\dfrac{-2}{200}=\dfrac{-1}{100}\)

Vì bạn tính A:6=28(dư 5)=>A=28.6+5=173

=>A*6=173*6=1038

Quá dễ lun !
A = 25 x 6 + 5 = 155
Giá trị của biểu thức A x 6 là : 155 x 6 = 930 

a,500+8075=8575

b,8075-500=7575

**** minh nhe !