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