a) \(12x-60+21-7x-5=0\)

\(\Rightarrow5x-44=0\)

\(\Rightarrow5x=44\)

\(\Rightarrow x=\frac{44}{5}\)

Vậy: \(x=\frac{44}{5}\)

e, / 2x - 1 / = 15

\(\Rightarrow\left[\begin{matrix}2x-1=15\\2x-1=-15\end{matrix}\right.\)\(\Leftrightarrow\left[\begin{matrix}2x=16\\2x=-14\end{matrix}\right.\)\(\Leftrightarrow\left[\begin{matrix}x=8\\x--7\end{matrix}\right.\)

Vây: \(x=-7;8\)

d, -4 . ( 2x+9) - (-8+3) -( x + 13 ) = 0

\(\Rightarrow-8x-36+8-3-x-13=0\)

\(\Rightarrow-9x-44=0\)

\(\Rightarrow-9x=44\)

\(\Rightarrow x=-\frac{44}{9}\)

Vậy: \(x=-\frac{44}{9}\)

c, 7 . x .( 2 + x ) - 7 . x .( x+3) = 14

\(\Rightarrow7x\left(2+x\right)-7x\left(x+3\right)=14\)

\(\Rightarrow7x.\left(2+x-x-3\right)=14\)

\(\Rightarrow7x.-1=14\)

\(\Rightarrow-7x=14\)

\(\Rightarrow x=-2\)

Vậy: \(x=-2\)

b, -2.(x+6) + 6. ( x-10)= 8

\(\Rightarrow-2x-12+6x-60-8=0\)

\(\Rightarrow4x-80=0\)

\(\Rightarrow4x=80\)

\(\Rightarrow x=\frac{80}{4}=20\)

Chúc bạn học tốt !!!

a, x - 32 + 11 = 21 - 33 + 7

\(\Rightarrow x-32+11-21+33-7=0\)

\(\Rightarrow x-21-21+33-7=0\)

\(\Rightarrow x-42+33-7=0\)

\(\Rightarrow x-9-7=0\)

\(\Rightarrow x-15=0\)

\(\Rightarrow\)\(x=15\)

Vậy: \(x=15\)

Chúc bạn học tốt :)

2)

\(\Leftrightarrow\left\{\begin{matrix}2ab+2ac+2bc=2\\2a^2+2b^2+2c^2=2\end{matrix}\right.\)

\(\Rightarrow2a^2+2b^2+2c^2-2ab-2ac-2bc=0\)

\(\Rightarrow\left(a^2-2ab+b^2\right)+\left(a^2-2ac+c^2\right)+\left(b^2-2bc+c^2\right)=0\)

\(\Rightarrow\left(a-b\right)^2+\left(a-c\right)^2+\left(b-c\right)^2=0\)

\(\Rightarrow\left\{\begin{matrix}a-b=0\\a-c=0\\b-c=0\end{matrix}\right.\)\(\Leftrightarrow a=b=c\)

Từ \(a^2+b^2+c^2=1\)

\(\Rightarrow3a^2=1\)

\(\Rightarrow a^2=\frac{1}{3}\)

\(\Rightarrow a=\frac{\sqrt{3}}{3}\)

\(\Rightarrow M=a+b+c=3a=3.\frac{\sqrt{3}}{3}=\sqrt{3}\)

Vậy: \(M=\sqrt{3}\)

Chúc bạn học tốt!!!

=x³-x²-2x²+2x+x-1

=x³-3x²+3x-1

=(x-1)³