a: =>4x-15+5x=0
=>9x=15
hay x=5/3
b: \(\Leftrightarrow6x^2+15x-6x^2+2=0\)
=>15x+2=0
hay x=-2/15
c: \(\Leftrightarrow x^2+5x+6-x^2-3x+10=6\)
=>2x+16=6
=>2x=-10
hay x=-5
\(a,4x-15+5x=0\\ 9x=15\\ x=\dfrac{5}{3}\\ b,6x^2+15x-6x^2+2=0\\ 15x=-2\\ x=-\dfrac{2}{15}\\ c,x^2+2x+3x+6-\left(x^2-2x+5x-10\right)=6\\ x^2+5x+6-x^2-3x+10=6\\ 2x+16=6\\ 2x=-10\\ x=-5\)
\(a.4x-5\left(3-x\right)=0\)
\(9x-15=0\)
\(9x=0+15\)
\(9x=15\)
\(x=15:9\)
\(x=\dfrac{5}{3}.\)
\(Vậy...\)
\(b.3x\left(2x+5\right)-2\left(3x^2-1\right)=0\)
\(15x+2=0\)
\(15x=0-2\)
\(15x=-2\)
\(x=-2:15\)
\(x=-\dfrac{2}{15}.\)
\(Vậy...\)
\(c.\left(x+2\right)\left(x+3\right)-\left(x-2\right)\left(x+5\right)=6\)
\(2x+16=6.\)
\(2x=6-16\)
\(2x=-10\)
\(x=-10:2\)
\(x=-5.\)
\(Vậy...\)
