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(-122) . x = 56 + 10.13.x
144.x = 56 + 130.x
144.x - 130.x = 56
14x = 56
x = 56 : 14
x = 4
Vậy x = 4
các bạn ơi mình đang cần gấp . Mình chỉ còn 20 phút thui . HUHU
Bài làm :
1) \(\frac{x+11}{4}=\frac{2x+4}{5}\)
\(\Leftrightarrow\left(x+11\right).5=4.\left(2x+4\right)\)
\(\Leftrightarrow5x+55=8x+16\)
\(\Leftrightarrow5x-8x=16-55\)
\(\Leftrightarrow-3x=-39\)
\(\Leftrightarrow x=\frac{-39}{-3}=\frac{39}{3}=13\)
2)\(\frac{x+4}{x+10}=\frac{3}{5}\)
\(\Leftrightarrow\left(x+4\right).5=\left(x+10\right).3\)
\(\Leftrightarrow5x+20=3x+30\)
\(\Leftrightarrow5x-3x=30-20\)
\(\Leftrightarrow2x=10\)
\(\Leftrightarrow x=\frac{10}{2}=5\)
3)\(\frac{x+8}{x+14}=\frac{2}{3}\)
\(\Leftrightarrow\left(x+8\right).3=\left(x+14\right).2\)
\(\Leftrightarrow3x+24=2x+28\)
\(\Leftrightarrow3x-2x=28-24\)
\(\Leftrightarrow x=4\)
ta có : 144.x=56+130.x
144.x-130.x=56
(144-130).x=56
14.x=56suy ra x=4
(-12)².x=56+10.13.x
<=>144.x=56+130.x
<=>144x-130x=56
<=>14x=56<=>x=4
Vậy x=4
Nhớ tick
Tách ra:
- \(2 + 4 = 6\)
- Dãy \(8+10+12+\cdots+98\) là cấp số cộng:
- Số đầu: 8, số cuối: 98, công sai: 2
- Số hạng: \(\left(\right. 98 - 8 \left.\right) / 2 + 1 = 46\)
- Tổng: \(46 / 2 \times \left(\right. 8 + 98 \left.\right) = 23 \times 106 = 2438\)
Tổng cả dãy:
\(6 + 2438 = \boxed{2444}\)Đặt B = 2 + 4 + 8 + 10 + 12 + ... + 98
+ Gọi A = 2 + 4 + 6 + 8 + 10 + 12 + ... + 98
A = (2 + 98) * (\(\frac{98-2}{2}\) + 1) : 2
A = 100 * \(\frac{98-2+2}{2}\) : 2
A = (100 : 2) * \(\frac{98}{2}\)
A = 50 * 49
A = 2450
⇒ B = 2450 - 6
B = 2444
Vậy B = 2444
nhớ like cho mk nhé, chúc bạn học tốt
(x-15):5+22=24
(X-15):5=24-22
(x-15):5=2
x-15=2.5
x-15=10
x=10+15
x=25
vậy x=25
( x-15) : 5 + 22=24
(x-15):5=24-22
(x-15):5=2
x-15=2. 5
x-15=10
x=15 +10
x=25
\(\frac{x-1}{99}+\frac{x-2}{98}+\frac{x-5}{95}=3+\frac{1}{99}+\frac{1}{98}+\frac{1}{95}\)
\(\Leftrightarrow\frac{x-1}{99}+\frac{x-2}{98}+\frac{x-5}{95}=1+\frac{1}{99}+1+\frac{1}{98}+1+\frac{1}{95}\)
\(\Leftrightarrow\frac{x-1}{99}+\frac{x-2}{98}+\frac{x-5}{95}=\frac{100}{99}+\frac{99}{98}+\frac{96}{95}\)
\(\Leftrightarrow\left(\frac{x-1}{99}-\frac{100}{99}\right)+\left(\frac{x-2}{98}-\frac{99}{98}\right)+\left(\frac{x-5}{95}-\frac{96}{95}\right)=0\)
\(\Leftrightarrow\frac{x-101}{99}+\frac{x-101}{98}+\frac{x-101}{95}=0\)
\(\Leftrightarrow\left(x-101\right).\left(\frac{1}{99}+\frac{1}{98}+\frac{1}{95}\right)=0\)
\(\Leftrightarrow x-101=0\)
\(\Leftrightarrow x=101\)
\(\frac{x-1}{99}+\frac{x-2}{98}+\frac{x-5}{95}=3+\frac{1}{99}+\frac{1}{98}+\frac{1}{95}\)
\(\Leftrightarrow\frac{x-1}{99}+\frac{x-2}{98}+\frac{x-5}{95}=1+\frac{1}{99}+1+\frac{1}{98}+1+\frac{1}{95}\)
\(\Leftrightarrow\frac{x-1}{99}+\frac{x-2}{98}+\frac{x-5}{95}=\frac{100}{99}+\frac{99}{98}+\frac{96}{95}\)
\(\Leftrightarrow\frac{x-1}{99}+\frac{x-2}{98}+\frac{x-5}{95}-\frac{100}{99}-\frac{99}{98}-\frac{96}{95}=0\)
\(\Leftrightarrow\left(\frac{x-1}{99}-\frac{100}{99}\right)+\left(\frac{x-2}{98}-\frac{99}{98}\right)+\left(\frac{x-5}{95}-\frac{96}{95}\right)=0\)
\(\Leftrightarrow\frac{x-101}{99}+\frac{x-101}{98}+\frac{x-101}{95}=0\)
\(\Leftrightarrow\left(x-101\right)\left(\frac{1}{99}+\frac{1}{98}+\frac{1}{95}\right)=0\)
Do \(\frac{1}{99}+\frac{1}{98}+\frac{1}{95}\ne0\)
Mà \(x-101=0\Leftrightarrow x=101\)
Vậy x = 101
(-12)\(^2\).\(x\) = -98 + 10.13.\(x\)
144\(x\) = - 98 + 130\(x\)
144\(x\) - 130\(x\) = -98
14\(x\) = -98
\(x=-98:14\)
\(x\) =- 7
Vậy \(x=7\)