a,-3

b,-201

c,421

d,90

a) 2x + 3x = -150

  x.(`2+3)=-150

  x.5=-150

  x=-150:5

  x=-30

Vậy x=-30

b) -24x + 7x = 3417

   x.(-24+7)=3417

   x.(-17)=3417

   x=3417:(-17)

  x=-201

Vậy x=-201

c) -3x + x = -842

   -3x+1x=-842

    x.(-3+1)=-842

   x.(-2)=-842

   x=-842:(-2)

   x=421

Vậy x=421

d) -7x + 2x = -450

     x.(-7+-2)=-450

    x.(-9)=-450

    x=-450:(-9)

   x=50

Vậy x=50

tick cho mình tròn 500 nha

Ta có:

\(7x^2+y^2+4xy-24x-6y+21=0\)

\(\Leftrightarrow y^2+4xy-6y+7x^2-24x+21=0\)

\(\Leftrightarrow y^2+2y\left(2x-3\right)+\left(2x-3\right)^2+3x^2-12x+12=0\)

\(\Leftrightarrow\left(y+2x-3\right)^2+3\left(x^2-4x+4\right)=0\)

\(\Leftrightarrow\left(y+2x-3\right)^2+3\left(x-2\right)^2=0\)

Mà \(\hept{\begin{cases}\left(y+2x-3\right)^2\ge0\\3\left(x-2\right)^2\ge0\end{cases}}\)

\(\Leftrightarrow\hept{\begin{cases}y+2x-3=0\\x-2=0\end{cases}\Leftrightarrow\hept{\begin{cases}x=2\\y=-1\end{cases}}}\)

Vậy cặp số  \(\left(x,y\right)=\left(2;-1\right)\)

mink vẫn chưa hiểu lắm bn ak giảng lại cho mink hiểu đi

Đề yêu cầu gì em?

\(x^2-5x+6=\left(x-2\right)\left(x-3\right)\)

\(x^2-7x+12=\left(x-2\right)\left(x-5\right)\)

\(x^2+x-12=\left(x-5\right)\left(x+6\right)\)

\(x^2-9x+20=\left(x-4\right)\left(x-5\right)\)

\(2x^2-3x+2=2\left(x+\dfrac{1}{2}\right)\left(x-2\right)\)

\(4x^2-7x-2=4\left(x-2\right)\left(x+\dfrac{1}{4}\right)\)

\(4x^2+15x+9=4\left(x+\dfrac{3}{4}\right)\left(x+3\right)\)

A) 34 + ( 9 - 21 ) = 3417 - (0 + 3417)

B) 9 - ( 55  - ( 49 + (-28 - 5 ))) = 13 -( 47 + -25 - 32 - 8 ))

C) |-1 - 1| - 1 + 1 = 0

D) |2 - 2| + 2 = 2

\(x=-0,206885594\) nhé =)

a)trường hợp 1:x+12=0=>x=-12

trường hợp 2:x-7=0=>x=7

b)(2+3)x=-150=>5x=-150=>x=-30

34+(9-21)=3417-(x+3417)

34+(-12)=3417-3417+x

22=0+x

22=x

Vậy x=22

34+(9-21)=3417-(x+3417)

34+(-12)=3417-(x+3417)

22          =3417-(x+3417)

3417-22=x+3417

3395      =x+3417

3395-3417=x

x=-22

kaito kid sai roi thu lai di

34 + ( 9 - 21 ) = 3417 - ( x + 3417 )

34 + ( -12 ) = 3417 - x - 3417

46 = x

=> x = 46

34 + ( 9 - 21 ) = 3417 - ( x + 3417 )

34 + ( -12 ) = 3417 - x - 3417

46 = x

=> x = 46

x=36 nha bạn