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\(2x+\frac{1}{2}=\frac{-5}{3}\)
\(2x=\frac{-5}{3}-\frac{1}{2}\)
\(2x=\frac{-10}{6}-\frac{3}{6}\)
\(2x=\frac{-13}{6}\)
\(x=\frac{-13}{6}:2\)
\(x=\frac{-13}{12}\)
a) \(({x^2} + 2x + 3) + (3{x^2} - 5x + 1) = ({x^2} + 3{x^2}) + (2x - 5x) + (3 + 1) = 4{x^2} - 3x + 4\);
b) \(\begin{array}{l}(4{x^3} - 2{x^2} - 6) - ({x^3} - 7{x^2} + x - 5) = 4{x^3} - 2{x^2} - 6 - {x^3} + 7{x^2} - x + 5\\ = (4{x^3} - {x^3}) + ( - 2{x^2} + 7{x^2}) - x + ( - 6 + 5) = 3{x^3} + 5{x^2} - x - 1\end{array}\);
c) \(\begin{array}{l} - 3{x^2}(6{x^2} - 8x + 1) = - 3{x^2}.6{x^2} - - 3{x^2}.8x + - 3{x^2}.1\\ = - 18{x^{2 + 2}} + 24{x^{2 + 1}} - 3{x^2} = - 18{x^4} + 24{x^3} - 3{x^2}\end{array}\);
d) \(\begin{array}{l}(4{x^2} + 2x + 1)(2x - 1) = (4{x^2} + 2x + 1).2x - (4{x^2} + 2x + 1).1 = 4{x^2}.2x + 2x.2x + 1.2x - 4{x^2} - 2x - 1\\ = 8{x^{2 + 1}} + 4{x^{1 + 1}} + 2x - 4{x^2} - 2x - 1 = 8{x^3} + 4{x^2} + 2x - 4{x^2} - 2x - 1 = 8{x^3} - 1\end{array}\);
e) \(\begin{array}{l}({x^6} - 2{x^4} + {x^2}):( - 2{x^2}) = {x^6}:( - 2{x^2}) - 2{x^4}:( - 2{x^2}) + {x^2}:( - 2{x^2})\\ = - \dfrac{1}{2}{x^{6 - 2}} + {x^{4 - 2}} - \dfrac{1}{2}{x^{2 - 2}} = - \dfrac{1}{2}{x^4} + {x^2} - \dfrac{1}{2}.\end{array}\);
g)
\(({x^5} - {x^4} - 2{x^3}):({x^2} + x)=x^3-2x^2\)
Noob ơi, bạn phải đưa vào máy tính ý solve cái là ra x luôn, chỉ tội là đợi hơi lâu
a, 4.(18 - 5x) - 12(3x - 7) = 15(2x - 16) - 6(x + 14)
=> 72 - 20x - 36x + 84 = 30x - 240 - 6x - 84
=> (72 + 84) + (-20x - 36x) = (30x - 6x) + (-240 - 84)
=> 156 - 56x = 24x - 324
=> 24x + 56x = 324 + 156
=> 80x = 480
=> x = 480 : 80 = 6
Vậy x = 6
5: (x-1)(x-5)=(x-1)(x-2)
=>(x-1)(x-5)-(x-1)(x-2)=0
=>(x-1)(x-5-x+2)=0
=>-3(x-1)=0
=>x-1=0
=>x=1
6: \(6\left(x-3\right)\left(x-4\right)-6x\left(x-2\right)=4\)
=>\(6\left(x^2-7x+12\right)-6x^2+12x=4\)
=>\(6x^2-42x+72-6x^2+12x=4\)
=>-30x=4-72=-68
=>\(x=\frac{68}{30}=\frac{34}{15}\)
7: -(x+3)(x-4)+(x+1)(x-1)=10
=>\(-\left(x^2-x-12\right)+x^2-1=10\)
=>\(-x^2+x+12+x^2-1=10\)
=>x+11=10
=>x=-1
8: (2x-1)(x-2)-(2x-7)(x+3)=3
=>\(2x^2-4x-x+2-\left(2x^2+6x-7x-21\right)=3\)
=>\(2x^2-5x+2-\left(2x^2-x-21\right)=3\)
=>\(2x^2-5x+2-2x^2+x+21=3\)
=>-4x+23=3
=>-4x=-20
=>x=5
9: \(\left(x-5\right)\left(4-x\right)-\left(x-1\right)\left(x+3\right)=-2x^2\)
=>\(-\left(x^2-9x+20\right)-\left(x^2+2x-3\right)=-2x^2\)
=>\(-x^2+9x-20-x^2-2x+3=-2x^2\)
=>7x-17=0
=>7x=17
=>x=17/7
10: (4x+1)(x-3)-(x-7)(4x-1)=15
=>\(4x^2-12x+x-3-\left(4x^2-x-28x+7\right)=15\)
=>\(4x^2-11x-3-4x^2+29x-7=15\)
=>18x-10=15
=>18x=25
=>x=25/18
11: \(\left(x+1\right)\left(x^2-x+1\right)-x\left(x^2-3\right)=4\)
=>\(x^3+1-x^3+3x=4\)
=>3x=4-1=3
=>x=1
12: \(\left(x-3\right)\left(x^2+3x+9\right)+x\left(5-x^2\right)=6x\)
=>\(x^3-27+5x-x^3=6x\)
=>6x=5x-27
=>x=-27
13: (3x-5)(x+1)-(3x-1)(x+1)=x-4
=>(x+1)(3x-5-3x+1)=x-4
=>-4(x+1)=x-4
=>-4x-4=x-4
=>-4x-x=0
=>-5x=0
=>x=0
14; 5(x-3)(x-7)-(5x+1)(x-2)=8
=>\(5\left(x^2-10x+21\right)-\left(5x^2-10x+x-2\right)=8\)
=>\(5x^2-50x+105-5x^2+9x+2=8\)
=>-41x=8-2-105=6-105=-99
=>x=99/41
1) \(5^{x+1}-5^x=20\Leftrightarrow5^x\left(5-1\right)=20\Leftrightarrow5^x=5\Leftrightarrow x=1\)
2) \(2^x+2^{x+4}=544\Leftrightarrow2^x\left(1+2^4\right)=544\Leftrightarrow2^x=32\Leftrightarrow x=5\)
3) \(4^{2x+1}+4^{2x}=80\Leftrightarrow4^{2x}\left(4+1\right)=80\Leftrightarrow16^x=16\Leftrightarrow x=1\)
4) \(3^{2x+2}+3^{2x+1}=108\Leftrightarrow3^{2x}\left(3^2+3\right)=108\Leftrightarrow9^x=9\Leftrightarrow x=1\)
5) \(7^{x+3}-7^{x+1}=16464\Leftrightarrow7^x\left(7^3-7\right)=16464\Leftrightarrow7^x=49\Leftrightarrow x=2\)
cảm ơn bn nha,
c:Ta có: \(5^{x+1}-5^x=20\)
\(\Leftrightarrow5^x\cdot5-5^x=20\)
\(\Leftrightarrow5^x\cdot4=20\)
\(\Leftrightarrow5^x=5\)
hay x=1
c: Ta có: \(2^x+2^{x+4}=544\)
\(\Leftrightarrow2^x+2^x\cdot16=544\)
\(\Leftrightarrow2^x\cdot17=544\)
\(\Leftrightarrow2^x=32\)
hay x=5
c: Ta có: \(4^{2x+1}+4^{2x}=80\)
\(\Leftrightarrow16^x\cdot4+16^x=80\)
\(\Leftrightarrow16^x\cdot5=80\)
\(\Leftrightarrow16^x=16\)
hay x=1
c: Ta có: \(3^{2x+2}+3^{2x+1}=108\)
\(\Leftrightarrow9^x\cdot9+9^x\cdot3=108\)
\(\Leftrightarrow9^x\cdot12=108\)
\(\Leftrightarrow9^x=9\)
hay x=1
c: Ta có: \(7^{x+3}-7^{x+1}=16464\)
\(\Leftrightarrow7^x\cdot343-7^x\cdot7=16464\)
\(\Leftrightarrow7^x\cdot336=16464\)
\(\Leftrightarrow7^x=49\)
hay x=2