bai 1: tim X
a) x + 5 . (-2) = 3 + (-5)
b) 2 . x - 4 = 5 . (-4)
Những câu hỏi liên quan
Bai 1: Tim so nguyen x biet:
x+(x+1)+(x+2)+...+35=0
Bai 2: Tim GTLN:
a) 8-(x+2)^2=E
b) -|x+2|+10=F
Bai 3: Tim x \(\in\)Z:
a)(2x-4)(x+4)<0
b)(x+5)(3x-12)>0
Bai 11: Cho:
S=1-2+3-4+5-6+...+19-20
a) S co\(⋮\)2; 3; 5 khong?
b) Tim tat ca cac uoc cua S
chi tiet gi minh nha
bai 1 tim x a) ( 4 1/2 - 2x) . 1 4/61 = 6 1/2 b) 2x + 1/2 = -5/3
Bai 1 Tim x
A) x nhan 4 phan 5 = 1 phan 2 nhan 1 phan 3
B ) x : 2 phan 5 = 2phan 3 + 1 phan 2
bai 1:tim GTNN cua bieu thucAx2+3x+7B(x-2)(x-5)(x2-7x-10)bai 2:tim GTLN cua bieu thucA11-10x-x2B[x-4](2-[x-4])bai 3:tim x,y sao choA2x2+9y2-6xy-6x-12y+2016 co GTNNB-x2+2xy-4y2+2x+10y-8 co GTLNbai 4 :a)cho x+y3;x2+y25.tinh x3+y3b)cho x-y5;x2+y215.tinh x3-y3
Đọc tiếp
bai 1:tim GTNN cua bieu thuc
A=x2+3x+7
B=(x-2)(x-5)(x2-7x-10)
bai 2:tim GTLN cua bieu thuc
A=11-10x-x2
B=[x-4](2-[x-4])
bai 3:tim x,y sao cho
A=2x2+9y2-6xy-6x-12y+2016 co GTNN
B=-x2+2xy-4y2+2x+10y-8 co GTLN
bai 4 :
a)cho x+y=3;x2+y2=5.tinh x3+y3
b)cho x-y=5;x2+y2=15.tinh x3-y3
Bai 1: Tim x
a)\(4^5+4^5+4^5+4^5.6^5+6^5+6^5+6^5+6^5+6^5=2^x\)
b)\(x\left(x+3\right)^{100}\)\(=\left(x+3\right)^{100}\)
a: \(\Leftrightarrow2^x=1024\cdot3+1024\cdot7776+7776\cdot5\)
\(\Leftrightarrow2^x=8004576\)
hay \(x\in\varnothing\)
b: \(\Leftrightarrow x\left(x+3\right)^{100}-\left(x+3\right)^{100}=0\)
\(\Leftrightarrow\left(x+3\right)^{100}\left(x-1\right)=0\)
=>x=-3 hoặc x=1
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Bai 1:
a) Cho A = 963 + 351 + x voi x thuoc N . Tim dieu kien cua x de A chia het cho 9 , de A khong chia hat cho 9
b) Cho B = 10 + 25 + x + 45 voi x thuoc N . Tim dieu kien cua x De B chia het cho 5 , B khong chia het cho 5
Bai 2 : Tim x thuoc N biet :
a) 1 + 2 + 3 + ..... + n = 325
b) 1 + 3 + 5 +... + ( 2n+1) = 144
c) 2 + 4 + 6 + ... + 2n = 756
bai 5 : tinh
a) tim x , biet (x+1) +(x+2 ) + ...+(x+100)=5750
b) chung minh rang B = 1/2^2 + 1/3^2 + 1/4^2 + ...+1/2021^2 < 1
giup mik luon voi
\(∘backwin\)
\(a ) ( x + 1 ) + ( x + 2 ) + ( x + 3 ) + ... + ( x + 100 ) = 5750\)
\( ( x + x + x + ... + x ) + ( 1 + 2 + 3 + ... + 100 ) = 5750 \)
\( 100 x + ( 1 + 100 ) ×100 : 2 = 5750\)
\(100 x + 5050 = 5750\)
\( 100 x = 5750 − 5050\)
\(100 x = 700\)
\(x = 700 : 100\)
\(x = 7\)
\(b,\) \(B=\)\(\dfrac{1}{2^2}+\dfrac{1}{3^2}+\dfrac{1}{4^2}+...+\dfrac{1}{2021^2}< \dfrac{1}{1.2}+\dfrac{1}{2.3}+\dfrac{1}{3.4}+...+\dfrac{1}{2020}+2021\)
\( B < 1 -\)\(\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+...+\dfrac{1}{2020}-\dfrac{1}{2021}\)
\(B<1-\)\(\dfrac{1}{2021}\)
\(B<\)\(\dfrac{2020}{2021}\)
\(\dfrac{2020}{2021}< 1\)
\(B<1\)
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a) (x+1) +(x+2 ) + ...+(x+100)=5750
= 100x + (1+2+3+...+100) = 5750
=100x + 5050 = 5750
--> 100x = 5750-5050=700
--> x=7
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b) Ta thấy: 1/2^2 < 1/2.3
1/3^2 < 1/3.4
...
1/2021^2 < 1/2021.2022
--> B=1/2^2 + 1/3^2 + 1/4^2 + ...+ 1/2021^2 < 1/2.3 + 1/3.4 + ... +1/2021.2022 (1)
Ta có: 1/2.3 + 1/3.4 + ... +1/2021.2022
=1/2 - 1/3 + 1/3 - 1/4 + ... + 1/2021 - 1/2022
=1/2 - 1/2022 < 1 (2)
Từ (1) và (2) --> B<1 (đpcm)
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Xem thêm câu trả lời
Bai 1: Tim ab ; biet ab = b x 9
Bai 2 : Tim ab, biet :
a) ab x 5 = 2ab b) ab = 4ab / 9.
Bai 3 : Tim ab, biet : a 2 = b x 5
Bai 4 : Tim cac so ab biet :
a) a x3 = bx9 b) a x4 = b x6.
Bai 5 :
a) Tim abc, biet a , b , c khac nhau va : a x bc = 91.
b) Tim a , b , c khac nhau biet aa x bc = 1001
bai 1giai phuong trinh
a) /x2-5x+5/ -2x2+10x-11
b) 8(x+1/x)2+4(x2+1/x2)-4(x2+1/x2)(x+1/x)2(x+4)2
bài 2 rut gon a((b-c)3+(c-a)3+(a-b)3)/((a2(b-c)+b2(c-a)+c2(a-b)
tim x,y 5x-3y2xy-11
bai 3 cho c2+2(ab-ac-bc)0, b kac c , a+b kac c
c/m (a2+(a-c)2)/(b2+(b-c)2)(a-c)/(b-c)
bai 4 cho x0; y0 x+y4 tim ginn ax+y+5/x+5/y
ai giai duoc bai nao thi giup mih voi mih xin cam on nhiu!!!!!!!!!
Đọc tiếp
bai 1giai phuong trinh
a) /x2-5x+5/= -2x2+10x-11
b) 8(x+1/x)2+4(x2+1/x2)-4(x2+1/x2)(x+1/x)2=(x+4)2
bài 2 rut gon a=((b-c)3+(c-a)3+(a-b)3)/((a2(b-c)+b2(c-a)+c2(a-b)
tim x,y 5x-3y=2xy-11
bai 3 cho c2+2(ab-ac-bc)=0, b kac c , a+b kac c
c/m (a2+(a-c)2)/(b2+(b-c)2)=(a-c)/(b-c)
bai 4 cho x>0; y>0 x+y<=4 tim ginn a=x+y+5/x+5/y
ai giai duoc bai nao thi giup mih voi mih xin cam on nhiu!!!!!!!!!