Bai2: Cho da thuc f(x)=x\(^2\)+4x-5
a, So -5 co phai la nghiem cua f(x) ko?
bViet tap hop S tat ca cac nghiem cua f(x)
Bai 3; Thu gon roi tim nghiem cua cac da thuc sau
a, f(x)=x(1-2x)+(2x\(^2\)-x+4)
b,g(x)=x(x-5)-x(x+2)+7x
c, h(x)=x(x-1)+1
moi nguoi xin hay giup to
Chung minh da thuc Q(x) = x^4 + 3x^2 + 1 khong co nghiem voi moi gia tri cua x
f(x) = 2 (x^3 - x) + x^2 - 3x + 3 - x^3
a) Thu gon hai da thuc tren roi xep theo luy thua giam dan cua bien
b) Tinh f(-1);g (1/2)
c) Tim f(x) + g(x);f(x) - g(x)
d) Tim gia tri cua x de f(x) = g(x) (giup mk voi mk dang can gap)
dang I. Tim gia tri bieu thuc
Bai 5: Cho x - y =9, tinh gia tri cua bieu thuc
B=\(\frac{4x-9}{3x+y}\)-\(\frac{4y+9}{3y+x}\)(x khac -3y, y khac -3x)
Bai 6: Hay viet cac da thuc duoi dang tong cua cac don thuc roi thu gon. tinh gia tri bieu thuc khi x=-1, y=1
a,D=4x(x+y)-5y(x-y)-4x\(^2\) b,E=(a-1)(x\(^2\)+1)-x(y+1)+(x+y\(^2\)-a+1)
moi nguoi giup minh di hu hu
Bai 4: Xac dinh he so m de cac da thuc sau nhan 1 lam nghiem
a,mx\(^2\)+2x+8 b, 7x\(^2\)+mx-1 c, x\(^5\)-3x\(^2\)+m
Bai5: Cho da thuc f(x)=x\(^2\)+mx +2
a, Xac dinh m de f(x) nhan -2 lam 1 nghiem
b, Tim tap hop cac nghiem cua f(x) ung voi gia tri vua tim duoc cua m
Bai 6: Tim da thuc f(X) roi tim nghien cua f(x) biet
\(x^3+2x^2\left(4y-1\right)-4xy^2-9y^3-f\left(x\right)=-5x^3+8x^2y-4xy^2-9y^3\)
Cho 2 da thuc A= 2x^3 + x^2 - 4x +x^3 + 3 ; B= 6x + 3x^3 -2x + x^2 - 5
a, Tinh tong hai da thuc A+B
b, Tinh hieu hai da thuc A-B
c, tim nghiem cua da thuc hieu A - B vua tim duoc o y b.
a)Cho vi du ve 1 don thuc ,1 da thuc nhung khong phai la don thuc ,2 don thuc dong dang voi nhau ,da thuc 1 bien
b)Hay viet 1 don thuc dong dang voi don thuc don thuc xy\(^3\) sao cho tai x=-1 y=2 gia tri cua don thuc do la so nguyen duong nho hon 10
Cho bieu thuc :
C = ( 1 - 3x ) . x - 2x . ( x - 1 ) + 8
a ) Thu gon C
b ) Tinh gia tri bieu thuc voi x = -3
c ) Tim x de C = 8
d ) Tim ngiem cua C
dau . la dau nhan nha cac bn
nhanh nhanh nha mk dang can gap
Cho da thuc p(x)= 6x^2-5x-1
q(x)= -2x^4+4x^3-3x^2+x
Tim nghiem Chung cua 2 da thuc