5x–52=10
x-1/3.x+1/5.x=-26/5
2/3.(x+9/5)-3/10.(5x-1/3)=7/15
Tìm x, y, z trong các câu sau :
a) -5x + 9y - 8z + 6 = 5
b) 12y + 5z - 6x - 20 = -10
c) 6z + 52 - 12x + 8y = 29
d) 120 - 5x + 6y = 5z + 8
giúp mình vớiiiiiiiiiiiiiiiii
5x .52 = 540
\(5^x.5^2=5^{40}\)
\(\Rightarrow5^x=5^{40}:5^2=5^{38}\)
=> x = 38
\(5^x\cdot5^2=5^{40}\)
\(\Leftrightarrow x+2=40\)
hay x=38
125:5x+52=26
\(125:5^x+5^2=26\)
\(\Rightarrow125:5^x+25=26\)
\(\Rightarrow125:5^x=26-25\)
\(\Rightarrow125:5^x=1\)
\(\Rightarrow5^x=125:1\)
\(\Rightarrow5^x=125\)
\(\Rightarrow5^x=5^3\)
\(\Rightarrow x=3\)
5x+x : 5=52
5*(5*x+x:5)=52*5
5*5*x+x:5*5=260
25*x+x=260
26*x=260
x=260*26
x=10
bạn chỉ mình phép trên được không, phép dưới mình viết sai
5x+x:5=52
=>5.5.x+x:5.5=260
=25x+x=260
26x=260
=>x=10
xy+14+2y+7x= -10
xy+x+y=2
xy-10+5x-3y=2
xy-1=3x+5y+4
|31-17|-|15-52|
1532+(-186)+(-1432)+(-14)+123
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\(xy+14+2y+7x=-10\)
\(\Rightarrow xy+7x+7y=-24\)
\(\Rightarrow x\left(y+7\right)+7y=-24\)
\(\Rightarrow x\left(y+7\right)+7y+49=-24+49\)
\(\Rightarrow x\left(y+7\right)+7\left(y+7\right)=25\)
\(\Rightarrow\left(x+7\right)\left(y+7\right)=25\)
\(\Rightarrow\left(x+7\right);\left(y+7\right)\inƯ\left(25\right)=\left\{\pm1;\pm5;\pm25\right\}\)
Xét bảng
x+7 | 1 | -1 | 5 | -5 | 25 | -25 |
y+7 | 25 | -25 | 5 | -5 | 1 | -1 |
x | 6 | -8 | -2 | -12 | 18 | -32 |
y | 18 | -32 | -2 | -12 | 6 | -8 |
Vậy.........................
\(xy+x+y=2\)
\(\Rightarrow x\left(y+1\right)+\left(y+1\right)=2+1\)
\(\Rightarrow\left(x+1\right)\left(y+1\right)=3\)
\(\Rightarrow\left(x+1\right);\left(y+1\right)\inƯ\left(3\right)=\left\{\pm1;\pm3\right\}\)
Xét bảng
x+1 | 1 | -1 | 3 | -3 |
y+1 | 3 | -3 | 1 | -1 |
x | 0 | -2 | 2 | -4 |
y | 2 | -4 | 0 | -2 |
Vậy.....................................
\(xy-10+5x-3y=2\)
\(\Rightarrow xy-5x-3y=12\)
\(\Rightarrow x\left(y-5\right)-3y+15=12+15\)
\(\Rightarrow x\left(y-5\right)-3\left(y-5\right)=27\)
\(\Rightarrow\left(x-3\right)\left(y-5\right)=27\)
\(\Rightarrow\left(x-3\right);\left(y-5\right)\inƯ\left(27\right)=\left\{\pm1;\pm3;\pm9;\pm27\right\}\)
Tự xét bảng như trên
\(xy-1=3x+5y+4\)
\(\Rightarrow xy-3x-5y=4+1\)
\(\Rightarrow x\left(y-3\right)-5y+15=1+4+15\)
\(\Rightarrow x\left(y-3\right)-5\left(y-3\right)=20\)
\(\Rightarrow\left(x-5\right)\left(y-3\right)=20\)
\(\Rightarrow\left(x-5\right)\left(y-3\right)\inƯ\left(20\right)=\left\{\pm1;\pm2;\pm4;\pm5;\pm10;\pm20\right\}\)
Xét bảng
x-5 | 1 | -1 | 2 | -2 | 4 | -4 | 5 | -5 | 10 | -10 | 20 | -20 |
y-3 | 20 | -20 | 10 | -10 | 5 | -5 | 4 | -4 | 2 | -2 | 1 | -1 |
x | 6 | 4 | 7 | 3 | 9 | 1 | 10 | 0 | 15 | -5 | 25 | -15 |
y | 23. | -17 | 13 | -7 | 8 | -2 | 7 | -1 | 5 | 1 | 4 | 2 |
Vậy......................................
Bài 1: tìm x TRÌNH BÀY LUÔN
1) 2x+20=122
2) 26-2x=20
3) 5x+205=295
4) 75+12:x=81
5) 3x-7=14
6) 45:(12-x)=3
7) 172-2.(x-30)=94
8) (x+52)-27=54
9) 72:3(x-3)=6
10) 19-(4x+1)=10
1) \(x=51\)
2) \(x=3\)
3) \(x=18\)
4) \(x=2\)
5) \(x=7\)
3.(-2)5x+8+52=1
giúp mình với ạ
\(3\cdot(-2)^{5x+8}+5^2=1\\\Rightarrow 3\cdot(-2)^{5x+8}+25=1\\\Rightarrow 3\cdot(-2)^{5x+8}=1-25\\\Rightarrow 3\cdot(-2)^{5x+8}=-24\\\Rightarrow (-2)^{5x+8}=-24:3\\\Rightarrow (-2)^{5x+8}=-8\\\Rightarrow (-2)^{5x+8}=(-2)^3\\\Rightarrow 5x+8=3\\\Rightarrow 5x=3-8\\\Rightarrow 5x=-5\\\Rightarrow x=-5:5\\\Rightarrow x=-1\)
Tìm x:
5x + 2x . ( 23 . 5 - 32 . 4 ) + 52 = 43
\(5x+2x\cdot\left(2^3\cdot5-3^2\cdot4\right)+5^2=4^3\)
\(\Rightarrow5x+2x\cdot\left(8\cdot5-9\cdot4\right)+25=64\)
\(\Rightarrow5x+2x\cdot\left(40-36\right)=64-25\)
\(\Rightarrow5x+2x\cdot4=39\)
\(\Rightarrow5x+8x=39\)
\(\Rightarrow x\cdot\left(5+8\right)=39\)
\(\Rightarrow13x=39\)
\(\Rightarrow x=\dfrac{39}{13}\)
\(\Rightarrow x=3\)
Vậy: ...