1). 20-[4* +(x-6)]=90
2). (х +3).(2х -4)=0
3). 1000:[30+(2" -6)]=3 +4
4). 3x+10 = 4?
5). 164– 2?(x-5)= 5.16
6). 4.2* -3 125
giúp mình với ạ
Bài 1: Tìm giá trị nhỏ nhất A= (x² +5x)² + 10x² +50x +124
B= (x +2)(x+3)(X-7)(x-8) – 2021
C= \(x^4\) +6x³ +7x² +6x +11
D= 2x² +20 +10y² +2xy – 6x +6y +123
F= (x+3)²(3x+8)(3x+10) -201
К- (2х-1)(х-1)х-3)(2x+3) + 19
5) (x– 5)(x – 1)= (x – 1)(x – 2)
6) 6(х - 3)(х — 4) - 6х(х — 2) = 4
7)-(x + 3)(x – 4) + (x + 1)(x – 1) = 10
8) (2x – 1)(x – 2) – (x + 3)(2x – 7) =3
9) (х - 5)(4 — х) — (х — 1)(х + 3) = -2x^2
10 (4x + 1)(x – 3) - (x- 7)(4x – 1)=15
11) (x + 1)(x² – x + 1) – x(x² – 3) = 4
12) (x – 3)(x² + 3x+9)+ x(5 – x²?) = 6x
13) (3x – 5)(x + 1)– (3x – 1)(x+ 1)=x - 4
14) 5(x – 3)(x – 7)– (5x+ 1)(x – 2)= 8
1/7=8/-x
3x/9=2/6
4/2/5:(-33/10)+x=-1/5/6
(x-2/1/4):(-5/6)=3
-8:(4/1/5x+3/10)=4/4/9
(5,5x-44):(-3/2)=30
(13/10x-15).(-5/14)=3
1/3.(x+5/2)=-2
chu y dau( //)la so tap phan con dau( /) la phan so
\(\frac{4}{\frac{2}{5}}:\left(-\frac{33}{10}\right)+x=-\frac{1}{\frac{5}{6}}\)
\(10:\left(-\frac{33}{10}\right)+x=-\frac{6}{5}\)
\(-\frac{100}{33}+x=-\frac{6}{5}\)
\(x=\frac{302}{165}\)
Tìm x :
a. 10 x X - 1 - 3 - 5 - 7 - .... - 19 = 2 + 4 + 6 + .... + 20 .
b. 3x / 2 + 3x / 6 + 3x / 12 + 3x / 20 + 3x / 30 = 10
a ) 10 x X - 1 - 3 - 5 - 7 - ... - 19 = 2 + 4 + 6 + ... + 20
10 x X - 1 - 3 - 5 - 7 - ... - 19 = 110
10 x X - ( 1 + 3 + 5 + 7 + ... + 19 ) = 110
10 x X - 100 = 110
10 x X = 110 + 100
10 x X = 210
X = 210 : 10
X = 21
a 10 x X-1-3-5-7-....-19 = 2+4+6+....+20
10xX-1-3-5-7-....-19=110
10xX=110+1+3+5+7+....+19
10xX=210
X=210:10
X=21
b là 4
Tính nhẩm: 1) 373737 . 73 - 37 . 737373 2)19 . 41414141 - 41 . 19191919 3)123456 . 456789456789 - 456789 . 123456123456 4)250 . 12 . 7 5)24 . 125 . 9 6)125 . 44 . 18 7)8 . 24 . 6 + 12 . 4 . 52 + 2 . 22 . 24 8)18. 58 . 2 - 9 . 27 . 4 + 12 . 69 . 3 9)30 . 85 . 3 + 18 . 72 . 5 - 45 . 37 . 2 - 9 . 20 . 10
1) \(373737.73-37.737373\)
\(=37.10101.73-37.73.10101\)
\(=0\)
2) \(19.41414141-41.19191919\)
\(=19.41.1010101-41.19.1010101\)
\(=0\)
3) \(123456.456789456789-456789.123456123456\)
\(=123456.456789.1000001-456789.123456.1000001\)
\(=0\)
4) \(250.12.7\)
\(=250.4.3.7\)
\(=\left(250.4\right).\left(3.7\right)\)
\(=1000.21\)
\(=21000\)
5) \(24.125.9\)
\(=3.8.125.9\)
\(=\left(3.9\right).\left(8.125\right)\)
\(=27.1000\)
\(=27000\)
6) \(125.44.18\)
\(=125.4.11.2.9\)
\(=\left(125.4.2\right).\left(11.9\right)\)
\(=1000.99\)
\(=99000\)
7) \(8.24.6+12.4.52+2.22.24\)
\(=48.24+48.52+48.22\)
\(=48\left(24+52+22\right)\)
\(=48.98\)
\(=48\left(100-2\right)\)
\(=48.100-48.2\)
\(=4800-96\)
\(=4704\)
8) \(18.58.2-9.27.4+12.69.3\)
\(=36.58-36.27+36.69\)
\(=36\left(58-27+69\right)\)
\(=36.100=3600\)
9) \(30.85.3+18.72.5-45.37.2-9.20.10\)
\(=90.85+90.72-90.37-90.20\)
\(=90\left(85+72-37-20\right)\)
\(=90.100=9000\)
1) 4x-(2x-5)=21
2) 14x+5=8x+10
3) 15+5x=3x+30
4) 2x-5=15-3x
5) 2(3x+5)+3(x+1)=6x+20
6) 4(x-3)+5(x-3)=18
1) 4x-(2x-5)=21
4x-2x+5=21
2x+5=21
2x=21 -5
2x=16
x=16/2
x=8
2)14x+5=8x+10
14x-8x=10-5
6x=5
x=5/6
3) 15+5x=3x+30
5x-3x=30-15
2x=15
x=15/2
Vậy x=15/2
Tìm x
1)(x+11)–(15–x) =–20
2)(2x–16)+(x–13)=(-2)4
3)(4x+35–x) –(x+12–52)=3x+(-2020)0
4)2(x–5)+3(x–4)=-44
5)3(x–6)–5(x+10)=-33
1) \(\Leftrightarrow x+11-15+x+20=0\)
\(\Leftrightarrow2x+16=0\)
\(\Leftrightarrow x=-8\)
2) \(\Leftrightarrow2x-16+x-13=16\)
\(\Leftrightarrow3x-45=0\)
\(\Leftrightarrow x=15\)
Những câu dưới bạn làm tương tự như vậy nhé
1)(x+11)–(15–x) =–20
x+11 - 15 + x = -20
x + ( 11 -15 ) = -20
x + ( -4 ) = -20
x = -20 - ( -4 )
x = -16
5) (x– 5)(x – 1)= (x – 1)(x – 2)
6) 6(х - 3)(х — 4) - 6х(х — 2) = 4
7)-(x + 3)(x – 4) + (x + 1)(x – 1) = 10
8) (2x – 1)(x – 2) – (x + 3)(2x – 7) =3
9) (х - 5)(4 — х) — (х — 1)(х + 3) = -2x^2
10 (4x + 1)(x – 3) - (x- 7)(4x – 1)=15
11) (x + 1)(x² – x + 1) – x(x² – 3) = 4
12) (x – 3)(x² + 3x+9)+ x(5 – x²?) = 6x
13) (3x – 5)(x + 1)– (3x – 1)(x+ 1)=x - 4
14) 5(x – 3)(x – 7)– (5x+ 1)(x – 2)= 8
minh ko biết toán lớp 8 mik lớp 4 mà giải hộ mik với :(
68 x 5 + 68 x 5, 444 + 556 + 6825 + 2175
12 739 - (7000 - 739)
bài 1:
1) 20 - 2(x+4)= 4
2) 30 - [ 4(x-2)+ 15]= 3
3) 14 ⋮(2.x + 3)
4) (3x - 24).7 = 2.73
5) (x + 1)3 = 27
6) (2x - 6).47=49
7) (10 + 2x) : 42011 = 42013
8) [(8x - 12) :4].33 = 36
9) 6⋮(x - 1)
10) (x + 5)⋮(x + 2)
mong mn giúp mình gấp với ạ ^^
1: Ta có: \(20-2\left(x+4\right)=4\)
\(\Leftrightarrow2\left(x+4\right)=16\)
\(\Leftrightarrow x+4=8\)
hay x=4
5: Ta có: \(\left(x+1\right)^3=27\)
\(\Leftrightarrow x+1=3\)
hay x=2