1 tim cac so nguyen x,y biet x/7=6/21 -5/y=20/28 1/2=x/12 x/8=-28/32 3/y=12/24 3/4=15/y 2 viet 3 phan so bang phan so -10/15
gia tri (x) :1 2 3 a 5 6 7 8 9 10
tan so(n) ;2 3 1 6 3 1 4 2 1 2 /N=25
biet so trung binh cong la 5,16 . tim a
giup minh voi
Tim cap so x,y thoa man:
(x+y-2)^2 +7 = 14 / |y-1| + |y-3|
|x+y+2| + 5 = 30 / 3 |y+5| + 6
(2-x) (x+1) = |y+1|
(x+3) (1-x) = |y|
(x-2) (5-x) = |2y+1| + 2
Xac dinh a va b biet nghiem cua da thuc f(x) = (x-1) (x+2) cx la nghiem cua da thuc g(x) = x^3 + a x^2 + bx + 2
bài 1 tìm x biết
a)(-2/3)^2.x=(-2/3)^5
b)(-1/3)^3.x=1/81
c)(x-1)^3=27
d)(2x+1)^2=25
e)(2x-3)^2=36
f)5^x+2=625
g)(x-1)^x+2=(x-1)^x+4
h)(2x-1)^3=-8
k)1/4.2/6.3/8.4/10.5/12....30/62.31/64=2^x
bai2 tim so nguyen duong n biet
a)32<2^n<128
b)2,16>=2^n>4
c)9,27<=3^n<=243
Tim x biet:
a.2|2x-3|=1/2
b.(x-1)^2=9/16
c.3/5(x-5/6)-1/2(3/2-1)=-1/4
d.1/3+1/6+1/10+......+2/x(x+1)=2015/2016
a,timx;y sao cho 2^x=4^y-1; 27^y= 3^x+8
b,tim ba phan so biet rang tong cua chung bang 3 3/7(hon so),cac tu cua chung ti le voi 3,4,5,cac mau cua chung ti lt voi5,1,2
tim cap so x,y nguyen biet :
a,\(|2x+3|+|2x-1|=\frac{8}{2|x-5|+2}\)
Hihihi.Hi moi nguoi.Minh se dat mot cau hoi ve dai so lop 7,mong moi nguoi chi giai><,boi vi toan minh hoc chua gioi lam nen co cac bai toan con thac mac,len day de mong nhan duoc su giup do,de toan nhu sau:(1)Da thuc P(x)=x2016 +2013x + 2012 co ngiem duong khong?Vi sao?. 2 Bai nua nhe(*^-^*):
(2)Cho hai da thuc: M(x)=2,52 -0,5x-x3-1
1/2N(x)=-x3+2,5x2-6+2x
a)Tim A(x)=M(x)-N(x).Sau do tim mot ngiem cua da thuc A(x)
b)Tim da thucB(x) biet B(x)=M(x)+N(x).Cho biet bac cua da thuc B(x).
(3)Cho da thuc:f(x)=ab2 + bx + c.Chung to neu f(x) co ngiem x=-1 thi b=a+c.
MOT BAI NUA THOI MA.NHA NHA NHA MOI NGUOI^_^:
(4)Cho hai da thuc:A=(-1/2axy3)2 va B=(-3a2 x2)3 (a la hang so khac 0).
a)Tinh M=A.B roi cho biet he so va phan bien cua M
b)Tim bac cua M.
AI CO CAU TRA LOI NHAN TIN TRA LOI CHO MINH BIET NHAAAAA.CAM ON!!!!!.
cho ham so y= f(x) =6/x
tinh f(1) ; f(1.5) ;f(2) ;f(3) ;f(-2/3)
tim x biet y=3 ; y=-2
tim y biet 1<x>3 ; 1.5 be hon hoac bang x lon hon hoac bang 6
diem nao trong cac diem sau day khong thuoc do thi ham s
A(-1;-6 ) ; B(-0.5 ;-12 ) ;C(-0.5 ; -13 ) ; D(-1/3 ; -3 )