Với x = -1

=> M(-1) = 1 - a + b = 0 => a - b = 1

=> M(-2) = 4 - 2a + b = 0 => 2a - b = 4

=> 2a - b - a + b = 4 - 1 = 3

=> a = 3

=> b = 3 - 1 = 2  

x = -1

\(\Rightarrow\)M ( -1 ) = 1 - a + b = 0 \(\Rightarrow\)a - b = 1

\(\Rightarrow\)M ( - 1 ) = 4 - 2a + b = 0 \(\Rightarrow\)2a - b = 4 

\(\Rightarrow\)2a - b - a + b = 4 -1 = 3

\(\Rightarrow\)a = 3          ;         b = 3 - 1 = 2

Giúp mình vs

(-6.37 * 0.4)*2.5= -2.548*2.5=-6.37

A (-6.37*0.4)*2.5=-6.37*(0.4*2.5)=-6.37*1=-6.37

B (-0.125*-5.3)*8=(-0.125*8)*(-5.3)=-1*(-5.3)=5.3

C -2.5*(-4)*(-7.9)=10*(-7.9)=-79

ko cho thêm gì hả bạn

tổng 4 góc của tứ giác luôn bằng 360^o

a, 3 : ( 1 - 3/2x ) = 4 : ( 2 - x )

<=> \(\frac{3}{1-\frac{3}{2}x}=\frac{4}{2-x}\)

<=> 3 ( 2 - x ) = 4 ( 1 - 3/2x )

<=> 6 - 3x = 4 - 6x

<=> -3x + 6x = 4 - 6

<=> 3x = -2

<=> x = -2/3

b, 2.3^x + 3^x-1 = 7( 3² + 2.6² )

b, 2.3^x + 3^x-1 = 7( 3² + 2.6² )

<=> 2.3^x + 3^x-1 = 7.81

<=> 3^x-1(2.3 + 1) = 7.81

<=> 3^x-1.7 = 7.81

<=> 3^x-1=81

<=> 3^x-1 = 3⁴

=> x - 1 = 4 => x = 5

1.I don't enjoy (laugh) laughing at by other people.           

2. I m angry at him for (tell,not) not telling me the truth.           

3.It is easy (fool) to fool by his lies.               

4 I expected to invite  to the party ,but I wasn't.

5 somtimes teenagers complain about not ( understand) understanding by their parents.

6.your compositions are supposed (write) to write in ink.

7.loc had a narrow escape.He was almost hit by a car.He barely avoided (hit) hitting by a speeding automobile .

8 Ms thompson is always willing to help if there is a problem in the office ,but she doesn't want (call) to call at home unless there is an emergency.

1. LAUGHING

2. NOT TELLING

3. TO FOOL

4. TO INVITE

5.UNDERSTANDING

6. TO WRITE

7. HITTING

8. TO CALL

E ở đâu ra vậy

đúng thế, diểm E là gì vậy bạn