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\(\frac{3x-1}{40x-5}=\frac{25-3x}{5x-34}\)
\(\Leftrightarrow\left(3x-1\right).\left(5x-34\right)=\left(40x-5\right).\left(25-3x\right)\)
\(\Leftrightarrow15x^2-102x-5x+34=1000x-120x^2-125-15x\)
\(\Leftrightarrow15x^2-107x+34=985x-120x^2-125\)
Làm tiếp nha không bk đúng kh nữa
\(\frac{3x-1}{40-5x}=\frac{25-3x}{5x-34}\)
\(\Rightarrow\left(3x-1\right)\left(5x-34\right)=\left(40-5x\right)\left(25-3x\right)\)
\(\Rightarrow3x\left(5x-34\right)-1\left(5x-34\right)=40\left(25-3x\right)-5x\left(25-3x\right)\)
\(\Rightarrow15x^2-102x-5x+34=1000-120x-125x+15x^2\)
\(\Rightarrow15x^2-107x+34=1000-245x+15x^2\)
\(\Rightarrow-107x+34=1000-245x\)
\(\Rightarrow-107x+245x=1000-34\)
\(\Rightarrow138x=966\)
\(\Rightarrow x=7\)
Mình chắc chắn đáp án này đúng.
\(\frac{3x-1}{40-5x}=\frac{25-3x}{5x-34}\)
\(\Leftrightarrow\left(3x-1\right).\left(5x-34\right)=\left(40-5x\right).\left(25-3x\right)\)
\(\Leftrightarrow15x^2-102x-5x+34=1000-120x-125x+15x^2\)
\(\Leftrightarrow-102x-5x+120x+125x=1000-34\)
\(\Leftrightarrow138x=966\)
\(\Leftrightarrow x=966:138\)
\(\Leftrightarrow x=7\)
=>(2x+3).(10x+2)=(5x+2).(4x+5)
=>(2x.10x)+(2x.2)+(3.10x)+(3.2)=(5x.4x)+(5x.5)+(2.4x)+(2.5)
=>20x2+4x+30x+6=20x2+25x+8x+10
=>20x2-20x2+4x-8x+30x-25x=10-6
=>0+4x-8x+30x-25x=4
=>-4x+30x-25x=4
=>26x-25x=4
=>x=4
B)=>(3x-1).(5x-34)=(40-5x).(25-3x)
=>15x2-102x-5x+34=1000-120x-125x+15x2
=>15x2-107x+34=1000-245x+15x2
=>15x2-15x2-107x+245x=1000-34
=>0-107x+245x=966
=>138x=966
=>x=7
A,=>(2x+3).(10x+2)=(5x+2).(4x+5)
=>(2x.10x)+(2x.2)+(3.10x)+(3.2)=(5x.4x)+(5x.5)+(2.4x)+(2.5)
=>20x2+4x+30x+6=20x2+25x+8x+10
=>20x2-20x2+4x-8x+30x-25x=10-6
=>0+4x-8x+30x-25x=4
=>-4x+30x-25x=4
=>26x-25x=4
=>x=4
\(\dfrac{3x-1}{40-5x}=\dfrac{25-3x}{5x-34}\\ \Leftrightarrow\left(3x-1\right)\left(5x-34\right)=\left(25-3x\right)\left(40-5x\right)\\ \Leftrightarrow15x^2-102x-5x+34=1000-125x-120x+15x^2\\ \Leftrightarrow15x^2-15x^2-102x-5x+125x+120x=1000-34\\ \Leftrightarrow138x=966\\ \Leftrightarrow x=\dfrac{966}{138}\\ \Leftrightarrow x=7\)
\(\frac{3x-1}{40-5x}=\frac{25-3x}{5x-34}\)
\(\Rightarrow\left(3x-1\right)\left(5x-34\right)=\left(40-5x\right)\left(25-3x\right)\)
\(\Rightarrow3x\left(5x-34\right)-\left(5x-34\right)=40\left(25-3x\right)-5x\left(25-3x\right)\)
\(\Rightarrow15x^2-102x-5x+34=1000-120x-125x+15x^2\)
\(\Rightarrow15x^2-97x+34=1000-245x+15x^2\)
\(\Rightarrow15x^2=1000-34-245x+97x+15^2\)
\(\Rightarrow15x^2=966-148x+15^x\)
\(\Rightarrow0=966-148x\)
\(\Rightarrow x=\frac{996}{148}=\frac{249}{37}\)
áp dụng tính chất của dãy tỉ số bằng nhau ta có;
\(\frac{3x-1}{40-5x}=\frac{25-3x}{5x-34}=\frac{3x-1+25-3x}{40-5x+5x-34}=\frac{24}{6}=4\)
suy ra:
\(\frac{3x-1}{40-5x}=4\)=>3x-1=4.(40-5x)
3x-1=160-20x
3x+20x=160+1
23x=161
x=161:23
x=7
vậy x=7