1> 234 + (345 - x ) =500
2> 456 -( x + 23 ) =326
3> ( 567 - x ) x 212 = 605
4> ( 5 x X - 15 ) :5 = 0
5> 14 x ( x - 7 ) = 210
6> 84 -4 x ( 2 x X +1 )= 48
tim x
.
a)234+(345-x)=500
b)456-(x+23)=326
c)(5.x-15):5=0
d)84-4.(2.x+1)=48
e)(x-76).54=0
f)(x-3).(x+4)=0
g)(x-6).(x-7)=0
h)(x-2).(x-3).(x-5)=0
ai nhanh mk tick cho
a) \(234+\left(345-x\right)=500\)
\(345-x=500-234\)
\(345-x=266\)
\(x=79\)
vay \(x=79\)
b) \(456-\left(x+23\right)=326\)
\(x+23=456-326\)
\(x+23=130\)
\(x=107\)
vay \(x=107\)
c) \(\left(5x-15\right):5=0\)
\(5x-15=0\)
\(5x=15\)
\(x=3\)
vay \(x=3\)
d) \(84-4\left(2x+1\right)=48\)
\(8x+4=84-48\)
\(8x+4=36\)
\(8x=32\)
\(x=4\)
vay \(x=4\)
e) \(\left(x-76\right).54=0\)
\(x-76=0\)
\(x=76\)
vay \(x=76\)
f) \(\left(x-3\right)\left(x+4\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x-3=0\\x+4=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=3\\x=-4\end{cases}}\)
vay \(\orbr{\begin{cases}x=3\\x=-4\end{cases}}\)
g) \(\left(x-6\right)\left(x-7\right)=0\)
\(\Rightarrow\orbr{\begin{cases}x-6=0\\x-7=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=6\\x=7\end{cases}}\)
vay \(\orbr{\begin{cases}x=6\\x=7\end{cases}}\)
h) \(\left(x-2\right)\left(x-3\right)\left(x-5\right)=0\)
\(\Rightarrow x-2=0\Rightarrow x=2\)hoac \(\orbr{\begin{cases}x-3=0\\x-5=0\end{cases}\Rightarrow}\orbr{\begin{cases}x=3\\x=5\end{cases}}\)
vay \(x=2\)hoac \(\orbr{\begin{cases}x=3\\x=5\end{cases}}\)
câu a,b thì chắc bn biết
c)(5.x-15):5=0
(5.x-15) =0.5
(5.x-15) =0
5.x =0+15
5.x =15
x =15:5
x =3
d)84-4.(2.x+1)=48
4.(2.x+1)=84-48
4.(2.x+1)=36
2.x+1 =36:4
2.x+1 =9
2.x =9-1
2.x =8
x =8:2
x =4
e)(x-76).54=0
x-76 =0:54
x-76 =0
x =0+76
x =76
f) (x-3).(x+4)=0
\(\Rightarrow\orbr{\begin{cases}x-3=0\\x+4=0\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=3\\x=-4\end{cases}}\)
Vậy x=3 hoặc x=-4
câu g,h làm tương tự
10 ^ ( 1 + 2 - 3 x 4 : 5 + 6 - 7 x 8 : 9 ) = ?
1 ^ 3 ^ 5 ^ 7 ^ 9 = ?
2 ^ 4 ^ 6 ^ 8 = ?
123+234+345+456+567+678+789+890+901+012 = ?
1 + 1 x 2 = ?
2 + 2 : 2
(3 + 3 - 3 X 3 : 3 ^ 3 ) bình phương cho 3 = ?
1 x A = 1 + A = 1 : A = 1 - A = 1 ^ A = 1 bình phương A = A = ?
sao câu 2+2:2 không có dấu = vậy
có vài câu không phải toán lớp 9 đâu
1) 5(x-3) (x-7)-(5x+1) (x-2)= -8
2) x(x+1) (x+2)-(x+4) (3x-5)= 84-5x
3) (9x2-5) (x+3)-3x2(3x+9)=(x-5) (x+4)-x(x-11)
4) (x2-4x+16) (x+4)-x(x+1) (x+2)+3x2=0
5) (8x+2) (1-3x)+(6x-1) (4x-10)=-50
6) (x2+2x+4) (2-x)+x(x-3) (x+4)-x2+24=0
7) (\(\dfrac{x}{2}\)+3) (5-6x)+(12x-2) (\(\dfrac{x}{4}\)+3)=0
1) Ta có: \(5\left(x-3\right)\left(x-7\right)-\left(5x+1\right)\left(x-2\right)=-8\)
\(\Leftrightarrow5\left(x^2-10x+21\right)-\left(5x^2-10x+x-2\right)=-8\)
\(\Leftrightarrow5x^2-50x+105-5x^2+9x+2+8=0\)
\(\Leftrightarrow-41x=-115\)
hay \(x=\dfrac{115}{41}\)
2) Ta có: \(x\left(x+1\right)\left(x+2\right)-\left(x+4\right)\left(3x-5\right)=84-5x\)
\(\Leftrightarrow x\left(x^2+3x+2\right)-\left(3x^2+7x-20\right)=84-5x\)
\(\Leftrightarrow x^3+3x^2+2x-3x^2-7x+20-84+5x=0\)
\(\Leftrightarrow x^3=64\)
hay x=4
3) Ta có: \(\left(9x^2-5\right)\left(x+3\right)-3x^2\left(3x+9\right)=\left(x-5\right)\left(x+4\right)-x\left(x-11\right)\)
\(\Leftrightarrow9x^3+27x^2-5x-15-9x^3-27x^2=x^2-x-20-x^2+11x\)
\(\Leftrightarrow-5x-15=10x-20\)
\(\Leftrightarrow-5x-10x=-20+15\)
\(\Leftrightarrow x=\dfrac{-5}{-15}=\dfrac{1}{3}\)
bài 1,tim x
1,X+(562+236)x5=569
2,(X-963):5=236+456
3,(X-236x6)x6=936
4,(X-569+987)-1236=4569
5,(X-590:5+2369)=78945
6,X+(5621+1236)x5=225690
7,X+2564:4=486x9
8,X+5640:4+1230=2650+4565
9,X+12x5x8+567=1000
10,(X+963)X5=2365+4560
11,(x+236x6):6=536
12,(X+569+987)+1236=20569
13,(X+5590:5+2369)=78945
14,Xx2+Xx3=2650
15,X+2+X+4+X+6+X+8=25760
16,X-9-Xx5=10248
17,(1238+2506):X+456=552
NẾU CÁC CẬU GIẢI ĐÚNG SẼ ĐƯỢC NHIỀU TÍCH HƠN 10 TÍCH
Wow, cũng có vẻ nhiều đấy nhưng mk cũng ko rảnh nên xl bạn nhé. Nếu hôm nào mk rảnh thì lm nha, bởi vì nhìn qua cũng đơn giản mà.
Bài 1 : Tính ( tính nhanh nếu có thể )
a) ( 257 × 139 – 257 × 39 ) : 100
b) 5 + 6 + 13 + 17 + .......+ 2017
c) 12 × 57 + 57 × 15 + 63 × 57
Bài 2 : Tìm x, biết :
a) 541 + ( 218 – x ) = 735
b) ( x – 50 ) : 25 = 8
c) ( x – 32 ) – 15 = 0
d) 234 + ( 345 – x ) = 500
e) 456 – ( x + 23 ) = 326
P/s : Làm được cả 2 bài thì mk cho 8 tick. Bài 1 : 3 tick, bài 2 : 5 tick. Giúp mk nhoa 😘😘
Bài 1 :
a) ( 257 x 139 - 257 x 39 ) : 100
= 257 x ( 139 - 39 ) : 100
= 257 x 100 : 100
= 257
a) ( 257 × 139 – 257 × 39 ) : 100
= [ 257 x ( 139 -39 ) ] : 100
= ( 257 x 100 ) :100
= 25700 :100
=257
b) 5 + 6 + 13 + 17 + .......+ 2017
= ( 5 + 2017 ) + ( 6 + 2016 ) + ( 7 + 2015 ) + ... + ( 1009 + 1013 ) + ( 1010 + 1012 ) + 1011
= 2022 + 2022 + 2022 + ... + 2022 + 2022 + 1011
= 2022 × 1006 + 1011
= 203514
c) 12 × 57 + 57 × 15 + 63 × 57
= 57 × ( 12 + 15 + 63 )
= 57 x 90
= 5130
Bài 2:
a) 541 + ( 218 - x ) = 735 b) ( x - 50 ) : 25 = 8 c) ( x - 32 ) - 15 = 0
( 218 - x ) = 735 - 541 ( x - 50 ) = 8 x 25 ( x - 32 ) = 0 + 15
( 218 - x ) = 194 x - 50 = 200 x - 32 = 15
x = 218 - 194 x = 200 + 50 x = 15 + 32
x = 24 x = 250 x = 47
Tính nhanh :
2, 5 * 8, 7 + 7, 5 * 8, 7 = ?
86 * 5 + 86 * 4 + 86 = ?
123,45 + 23,56 + 76,44 + 54,55 = ?
456 x 45 + 456 x 10 – 456 x 55 = ?
25 x 8 x 17 x 50 = ?
(12 x 2 + 12 x 4 – 12 x 6) : (2 + 4 +…….+12 + 14) = ?
(1+3+5+7+9+11+13+15) : (32 x 2) = ?
(24 x 6 + 4 x 24) : (49 – 24 x 2) = ?
(1+2+3+…..+98+99+100) : 5050 = ?
35 x 11 x 0,1 x 0,25 x 100 x (3 : 0,4 – 7,5) = ?
ai giải nhanh và đúng nhất m k cho, trình bày ra nhé
123,45 + 23,56 +76,44 + 54,55
= (123,45 + 54,55) + (23,56 + 76,44)
= 178 + 100
= 278
456 x 45 + 456 x 10 + - 456 x 55
=456 x (45 +10-55)
=456 x 0
=0
2,5 x 8,5 + 7,5 x 8,5
=8,5 x (2,5 +7,5)
= 8,5 x 10
= 85
86 x 5 + 86 x 4 + 86
= 86 x (5+4+1)
= 86 x10
860
25 x 8 x 17 x 50
= 50 x 4 x 17 x 50
= 200 x 17 x 50
= 200 x 50 x 17
= 10000 x 17
= 170000
(12 x 2 + 12 x 4 - 12 x 6 ) : ( 2 + 4 + 6 +... + 12 +14)
=(12 x (2 + 4 - 6) ) : ( 2 + 4 + 6 + ... + 12 + 14 )
= (12 x 0 ) : (2 + 4 + 6 + ... + 12 + 14 )
=0 : ( 2 + 4 + 6 + ... + 12 + 14)
= 0
a)5. ( x + 35 ) = 515
b) (x+7):3=14c) 72:(x–15)=8
d) 19+(x+23)=50
e) (18–x) + 23 =29
f) 56–(x+14)=22g) (2x +1)–7=14
h) 3. (x+1)–32=67i) 70–5. (x–3)=45
j) 200–8. (2x+7)=112
k) 123–(x+4). 5 =38
\(a,\Rightarrow x+35=103\\ \Rightarrow x=68\\ b,\Rightarrow x+7=42\\ \Rightarrow x=35\\ c,\Rightarrow x-15=9\\ \Rightarrow x=24\\ d,\Rightarrow x+23=31\\ \Rightarrow x=8\\ e,\Rightarrow18-x=6\\ \Rightarrow x=12\\ f,\Rightarrow x+14=34\\ \Rightarrow x=20\\ g,\Rightarrow2x+1=21\\ \Rightarrow x=11\\ h,\Rightarrow3\left(x+1\right)=99\\ \Rightarrow x+1=33\Rightarrow x=32\\ i,5\left(x-3\right)=25\\ \Rightarrow x-3=5\\ \Rightarrow x=8\\ j,\Rightarrow8\left(2x+7\right)=88\\ \Rightarrow2x+7=11\Rightarrow x=2\\ k,\Rightarrow5\left(x+4\right)=85\\ \Rightarrow x+4=17\\ \Rightarrow x=13\)
Bai 2 :
\(\hept{\begin{cases}x+y=7\\x-7=13\end{cases}\Leftrightarrow\hept{\begin{cases}x+y=7\\x=20\end{cases}}}\)
Thay x vào phương trình đầu ta có :
\(20+y=7\Leftrightarrow y=-13\)
Vậy \(\left\{x;y\right\}=\left\{20;-13\right\}\)
Thử \(20-13=7\); \(20-7=13\)( thỏa mãn )
Bai 1 Tim x biet
a)162+(15-x0=125
b)x^3*x^2=2^7/4
c)5(x+27)=200
d)x-3=6-(19-23)
e)(x+32)-145=92
f) 2*3^x=162
g)9x-9=3^2/3
h)162-(15+x)=148
Bai 2 Thuc hien phep tinh
a)12+14+16+18+...+86+88
b)217+[43+(-217)+(-23)]
c) (-345)+[(-724)+345+224]
d)2^3*3-(12-36)
mình giải ý c
5(x+27)=200
(x+27)=200:5
(x+27)=40
x=40-27
x=13