\(\text{a) 2(x+3)-3(x-1)=2}\)
\(2x+6-3x+3=2\)
\(2x-3x=2-3-6\)
\(-x=-7\)
\(x=7\)
\(\text{b) 7-(x-2)=5(2x-3)}\)
\(7-x+2=10x-15\)
\(-x-10x=-15-2-7\)
\(-11x=-24\)
\(x=-24:\left(-11\right)\)
\(x=\frac{24}{11}\)
\(\text{c) 32-4(0,5y-5)=3y+2}\)
\(32-2y+20=3y+2\)
\(-2y-3y=2-20-32\)
\(-y=-50\)
\(y=50\)
\(\text{d) 3(x-1)-x=2x-3}\)
\(3x-3-x=2x-3\)
\(3x-x-2x=-3+3\)
\(0=0\)( vô nghiệm )
a) 2(x + 3) - 3(x - 1) = 2
<=> 2x + 6 - 3x + 3 = 2
<=> -x + 9 = 2
<=> -x = -2 - 9
<=> -x = -7
<=> x = 7
b) 7 - (x - 2) = 5(2x - 3)
<=> 7 - x + 2 = 10x - 15
<=> 9 - x = 10x - 15
<=> 9 - x - 10 = -15
<=> 9 - 11x = -15
<=> -11x = -15 - 9
<=> -11x = -24
<=> x = 24/11
c) 32 - 4(0,5y - 5) = 3y + 2
<=> 32 - 2y + 20 = 3y + 2
<=> 52 - 2y = 3y + 2
<=> 52 - 2y - 3y = 2
<=> 52 - 5y = 2
<=> -5y = 2 - 52
<=> -5y = -50
<=> y = 10
\(e,x^2+2x-4=-12+3x+x^2\)
\(x^2-x^2+2x-3x=-12+4\)
\(-x=-8\)
\(x=8\)
\(\text{g) x(x-1)-x(x+3)=15}\)
\(2x-x-2x-3x=15\)
\(-4x=15\)
\(x=15:\left(-4\right)\)
\(x=\frac{15}{-4}\)
\(\text{h) x(x-1)=x(x+3)}\)
\(2x-x=2x+3x\)
\(2x-x-2x-3x=0\)
\(-4x=0\)
\(\Rightarrow x=0\)
\(\text{i) x(2x-3)-x^2+2=x(x-5)-1}\)
\(3x-3x-x^2+2=2x-5x-1\)
\(3x-3x-2x+5x-x^2=-1-2\)
\(3x-x.x=-3\)
\(x.\left(3-1\right)=-3\)
\(\)\(x.2=-3\)
\(x=-3:2\)
\(x=\frac{-3}{2}\)
\(k,\left(x-1\right)\left(x+3\right)=x^2-4\)
\(\left(x-1\right).x+\left(x-1\right).3=x^2-4\)
\(2x-x+3x-4=x^2-4\)
\(2x-3x-x^2=-4+4\)
\(-x-x.x=0\)
\(-x.\left(1-x\right)=0\)
\(\Rightarrow\orbr{\begin{cases}-x=0\\1-x=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=0\\x=1\end{cases}}}\)
\(\Rightarrow x\in\left\{0;1\right\}\)
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