Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
talaays đơn thức nhân với từng hạng tử của đa thức
rồi cộng tích lại với nhau
rồi tìm x
nha bn
a)
<=> 10x - 35 + 16x - 10 = 5
<=> 10x + 16x = 5 + 35 + 10
<=> 26x = 50
<=> x = 50/26 = 25/13
a, \(4\left(18-5x\right)-12\left(3x-7\right)=15\left(2x-16\right)-6\left(x+14\right)\)
\(\Leftrightarrow72-20x-36x+84=30x-240-6x-84\)
\(\Leftrightarrow156-56x=24x-324\)
\(\Leftrightarrow-80x+480=0\Leftrightarrow x=-6\)
b, \(5\left(3x+5\right)-4\left(2x-3\right)=5x+3\left(2x-12\right)+1\)
\(\Leftrightarrow15x+25-8x+12=5x+6x-36+1\)
\(\Leftrightarrow7x+37=11x-35\)
\(\Leftrightarrow-4x+72=0\Leftrightarrow x=18\)
c, \(2\left(5x-8\right)-3\left(4x-5\right)=4\left(3x-4\right)+11\)
\(\Leftrightarrow10x-16-12x+15=12x-16+11\)
\(\Leftrightarrow-2x-1=12x-5\)
\(\Leftrightarrow-14x+4=0\Leftrightarrow x=\frac{2}{7}\)
d, \(5x-3\left\{4x-2\left[4x-3\left(5x-2\right)\right]\right\}=182\)
\(\Leftrightarrow5x-3\left[4x-15x+6\right]=182\)
\(\Leftrightarrow5x-3\left(-11x+6\right)=182\)
\(\Leftrightarrow5x+33x-18-182=0\)
\(\Leftrightarrow38x-200=0\Leftrightarrow x=\frac{100}{19}\)
\(a.\left(10x+9\right)x-\left(5x-1\right)\left(2x+3\right)=8.\)
\(\Leftrightarrow10x^2+9x-\left(10x^2+15x-2x-3\right)=8\)
\(\Leftrightarrow10x^2+9x-10x^2-13x+3=8\)
\(\Leftrightarrow-4x+3=8\)
\(\Leftrightarrow-4x=5\)
\(\Leftrightarrow x=-\frac{5}{4}\)
\(b.\left(3x-5\right)\left(7-5x\right)+\left(5x-2\right)\left(3x-2\right)-2=0\)
\(\Leftrightarrow21x-15x^2-35+25x+15x^2-10x+6x-4-2=0\)
\(\Leftrightarrow42x-41=0\)
\(\Leftrightarrow42x=41\)
\(\Leftrightarrow x=\frac{41}{42}\)
a) (3x - 1)(2x + 7) - (x + 1)(6x - 5) = 16
6x2 + 21x - 2x - 7 - 6x2 + 5x - 6x + 5 = 16
(6x2 - 6x2) + (21x - 2x + 5x - 6x) + (-7 + 5) = 16
18x - 2 = 16
18x = 18
x = 1
Vậy x = 1
b) (10x + 9)x - (5x - 1)(2x + 3) = 8
10x2 + 9x - 10x2 - 15x + 2x + 3 = 8
(10x2 - 10x2) + (9x - 15x + 2x) + 3 = 8
-4x + 3 = 8
-4x = 5
x = \(\frac{-5}{4}\)
Vậy x = \(\frac{-5}{4}\)
c) x(x + 1)(x + 6) - x3 = 5x
(x2 + x)(x + 6) - x3 = 5x
x3 + 7x2 + 6x - x3 = 5x
7x2 + 6x = 5x
x(7x + 6) = 5x
=> 7x + 6 = 5
7x = -1
x = \(\frac{-1}{7}\)
Vậy x = \(\frac{-1}{7}\)
d) (3x - 5)(7 - 5x) + (5x + 2)(3x - 2) - 2 = 0
21x - 15x2 - 35 + 25x + 15x2 - 10x + 6x - 4 - 2 = 0
(-15x2 + 15x2) + (21x + 25x - 10x + 6x) + (-35 - 4 - 2) = 0
42x - 41 = 0
42x = 41
x = \(\frac{41}{42}\)
Vậy x = \(\frac{41}{42}\)
Giải tiêu biểu câu a nhé.
a/ \(5x\left(2x-7\right)+2x\left(8-5x\right)=5\)
\(\Leftrightarrow19x+5=0\)
\(\Leftrightarrow x=-\frac{5}{19}\)
a)(3x-1)(2x+7)-(x+1)(6x-5)=16
=6x^2+21x-2x-7-(6x^2-5x+6x-5)=16
=6x^2+21x-2x-7-6x^2+5x-6x+5=16
=18x-2=16
18x=16+2
18x=18
x=1
vậy x=1
b)(10x+9)x-(5x-1)(2x+3)=8
10x^2+9x-(10x^2+15x-2x-3)=8
10x^2+9x-10x^2-15x+2x+3=8
-4x+3=8
-4x=8-3
-4x=5
x=-5/4.
vay x=-5/4
Answer:
\(6x^2-\left(2x+3\right)\left(3x-2\right)=7\)
\(\Rightarrow6x^2-\left(6x^2+9x-4x-6\right)=7\)
\(\Rightarrow6x^2-\left(6x^2+5x-6\right)=7\)
\(\Rightarrow6x^2-6x^2-5x+6=7\)
\(\Rightarrow-5x+6=7\)
\(\Rightarrow-5x=1\)
\(\Rightarrow x=\frac{-1}{5}\)
\(5x\left(12+7\right)-3x\left(80x-5\right)=-100\)
\(\Rightarrow5x.19-240x^2+15x=-100\)
\(\Rightarrow95x-240x^2+15x=-100\)
\(\Rightarrow-240x^2+110x+100=0\)
\(\Rightarrow-24x^2-11x-10=0\)
\(\Rightarrow24\left(x^2-\frac{11}{24}x+\frac{121}{2304}\right)-\frac{1081}{96}=0\)
\(\Rightarrow24\left(x-\frac{11}{48}\right)^2-\frac{1081}{96}=0\)
\(\Rightarrow24\left(x-\frac{11}{48}\right)^2=\frac{1081}{2304}\)
\(\Rightarrow\left(x-\frac{11}{48}\right)^2=\left(\frac{\pm\sqrt{1081}}{48}\right)^2\)
\(\Rightarrow\orbr{\begin{cases}x-\frac{11}{48}=\frac{\sqrt{1081}}{48}\\x-\frac{11}{48}=\frac{-\sqrt{1081}}{48}\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{\sqrt{1081}+11}{48}\\x=\frac{11-\sqrt{1081}}{48}\end{cases}}\)
\(\left(3x-5\right)\left(7-5x\right)-\left(5x-2\right)\left(2-3x\right)=4\)
\(\Rightarrow\left(21x-15x^2-35+25x\right)-\left(10x-15x^2-4+6x\right)-4=0\)
\(\Rightarrow36x-15x^2-35-16x+15x^2+4-4=0\)
\(\Rightarrow\left(-15x^2+15x^2\right)+\left(36x-16x\right)+\left(-35+4-4\right)=0\)
\(\Rightarrow30x-35=0\)
\(\Rightarrow x=\frac{7}{6}\)