Ta có : \(\left|x\right|=5\Rightarrow x=5;x=-5\)
Với x = 5 ; y = 1 => A = 25 + 20 - 3 = 42
Với x = -5 ; y = 1 => A = 25 - 20 - 3 = 2
thuc hien phep tinh roi tinh gia tri bieu thuc
x(x2-y)-x2(x+y)+y(x2-x)
tai x=2012
y=1/5
Cho bieu thuc A = \(^{x2+4x+3}\)
a Tinh gia tri bieu thuc tai x= \(\frac{-1}{2}\)
b Tinh gia tri x de bieu thuc A bang 0
cho xyz la cac so thuc thoa man y+z+1/x=x+z+2/y=x+y+2/z=1/x+y+z tinh gia tri bieu thuc A=2016.x+y^2017+z^2017
tinh gia tri bieu thuc dai so x2 y3 +xytai x =1 va y =\(\frac{1}{2}\)
ai tra loi nhanh va dung nhat thi toi se tick cho toi co den 10nick lan
1/Hay viet bieu thuc dai do bieu thi chu vi cua hinh chu nhat co chieu dai hon 2 lan chieu rong 3m
2/ Hay viet bieu thuc dai so bieu thi chu vi cua hinh chu nhat co 3 lan chieu ronh hon chieu dai 8m
3/ hay viet bieu thuc dai so bieu thi the tich cua hinh hop chu nhat co chieu dai hon chieu ronh 4cm va hon chieu cao 2cm
4/ hay viet bieu thuc dai so bieu thi :
a) tong cua x^2 va 3y
b) tong cac binh phuong cua a va b
Tinh GT bieu thuc M = 21x2y + 4xy2 voi x,y thoa man :
(x-2)4-(2y-1)2014 < hoac =4
O Da Lat, gia tao la x(d/kg) va gia nho la y(d/kg). Hay viet bieu thuc dai so bieu thi so tien mua:
a) 5 kg tao va 8 kg nho.
b)10 hop tao va 15 hop nho, biet moi hop tao co 12 kg va moi hop nho co 10 kg.
Moi bieu thuc tim duoc o 2 cau tren co la da thuc ko?
cho x/2=y/5=z/5. Hay tinh gia tri cua bieu thuc
A =x-y+z /x+2y-z
cho bieu thuc:
A=(6-2/3+1/2)-(5+5/3-3/2)-(3-7/3+5/2)
hay tinh gia tri cua A theo hai cach
cach 1:truoc het tinh gia tri tung bieu thuc trong ngoac
cach 2:bo dau ngoac roi nhom cac so hang thich hop
