Question

tìm x

2x+143=557

2x²+12x-23=-41

3x³+9x²+9x+3=0

 

Answer 1

a)\(2x+143=557\)

\(\Leftrightarrow2x=557-143\)

\(\Leftrightarrow2x=414\)

\(\Leftrightarrow x=414\div2\)

\(\Leftrightarrow x=207\)

Vậy x = 207

Answer 2

\(2x^2+12x-23=-41\)

\(\Rightarrow2x^2-12x+18=0\)

\(\Rightarrow2x^2-4x-9x+18=0\)

\(\Rightarrow2x.\left(x-2\right)-9.\left(x-2\right)=0\)

\(\Rightarrow\left(x-2\right).\left(2x-9\right)=0\)

....

Answer 3

b) \(2x^2+12x-23=-41\)

\(\Leftrightarrow2x\left(x+6x\right)=-41+23\)

\(\Leftrightarrow2x\left(x+6x\right)=-18\)

\(\Leftrightarrow x\left(x+6x\right)=-18\div2\)

\(\Leftrightarrow x^2+6x^2=-9\)(1)

Vì \(\hept{\begin{cases}x^2\ge0\\6x^2\ge0\end{cases}}\Rightarrow x^2+6x^2\ge0\)[Trái với (1)]

Vậy phương trình vô nghiệm

Answer 4

TÊN HAY QUÁ HA TÊN LINH TINH

COMMENT THẾ THÔI ĐÙA MÀ TÊN HAY ĐẤY NHƯNG KHÔNG HAY BẰNG TÊN XUÂN MAI

Answer 5

\(3x^3+9x^2+9x+3=0\)

<=>\(3.\left(x^3+3x^2+3x+1\right)=0\)

<=>\(3.\left(x^3+x^2+2x^2+2x+x+1\right)=0\)

<=> \(3.\left(x+1\right)^3=0\)

<=> \(x+1=0\)

....

Answer 6

x=207

x=-3

x=-1

Answer 7

a) \(2x+143=557\)

\(\Rightarrow2x=414\)

\(\Rightarrow x=414:2=207\)

b) \(2x^2+12x-23=-41\)

\(\Rightarrow2x^2+6x+6x=-18\)

\(\Rightarrow2x^2+6x+6x+18=0\)

\(\Rightarrow2x.\left(x+3\right)+6.\left(x+3\right)=0\)

\(\Rightarrow\left(x+3\right).\left(2x+6\right)=0\)

.........................

Answer 8

x=207

x=-3

x=-1

Answer 9

\(3x^3+9x^2+9x+3=0\)

\(\Leftrightarrow3\left(x^3+3x^2+3x+1\right)=0\)

\(\Leftrightarrow3\left(x+1\right)^3=0\)

\(\Leftrightarrow x+1=0\)

\(\Leftrightarrow x=0-1\)

\(\Leftrightarrow x=-1\)

Answer 10

x=207

x=-3

x=-1

Answer 11

x=207

x=-3

x=-1

Answer 12

x=207

x=-3

x=-1