tinh gia tri cua bieu thuc
1995-321*3-6020:35
cho x+y =1 . tinh gia tri cua bieu thuc A=x^3+y^3+3xy
chox-y=1. tinh gia tri cua bieu thuc B=x^3-y^3-3xy
cho x+y=1 . tinh gia tri cua bieu thuc C=x^3+y^3+3xy(x^2+y^2)+6x^2*y^2(x+y)
Câu 1: Ta có: A = \(x^3+y^3+3xy=x^3+y^3+3xy\times1=x^3+y^3+3xy\left(x+y\right)\)
\(=\left(x+y\right)^3=1^3=1\)
Câu 2: Ta có: \(B=x^3-y^3-3xy=\left(x-y\right)\left(x^2+xy+y^2\right)-3xy\)
\(=x^2+xy+y^2-3xy=x^2-2xy+y^2=\left(x-y\right)^2=1^2=1\)
Câu 3: Ta có: \(C=x^3+y^3+3xy\left(x^2+y^2\right)-6x^2.y^2\left(x+y\right)\)
\(=x^3+y^3+3xy\left(x^2+2xy+y^2-2xy\right)+6x^2y^2\)
\(=x^3+y^3+3xy\left(x+y\right)^2-3xy.2xy+6x^2y^2\)
\(=x^3+y^3+3xy.1-6x^2y^2+6x^2y^3\)
\(=x^3+y^3+3xy\left(x+y\right)=\left(x+y\right)^3=1^3=1\)
Tinh gia tri cua bieu thuc:
2,34 : (2,34 - 1,09) x 35 + 21,086
Tinh gia tri cua bieu thuc:
2,34 : (2,34 - 1,09) x 35 + 21,086
2,34 : (2,34 - 1,09) x 35 + 21,086
= 2,34 : 1,25 x 35 + 21,086
= 1,872 x 35 + 21,086
= 65,52 + 21,086 86,606
Chúc bạn học tốt !!!!!!!!!!!!!!!!!!!!!!
2,34 : ( 2,34 - 1,09 ) × 35 + 21,086
= 2,34 : 1,25 × 35 + 21,086
= 1,872 × 35 + 21,086
= 65,52 + 21,085
= 86,606
Cho mk 1 tk nhé
bai 1: Tinh gia tri cua bieu thuc:
a) 12 : { 390 : [ 500 - ( 125 + 35 . 7 ) ] }
b) 12000 - ( 1500 . 2 + 1800 . 3 + 12 . 2 : 3 )
a) 12 : { 390 : [ 500 - ( 125 + 35. 7 ) ] }
= 12 : { 390 : [ 500 - ( 125 + 245 ) ] }
= 12 : { 390 : [ 500 - 370 ] }
= 12 : { 390 : 130 }
= 12 : 3
= 4
b) 12000 - ( 1500 .2 + 1800 .3 + 12 . 2 : 3 )
= 12000 - ( 3000 + 5400 + 8 )
= 12000 - 8408
= 3592
a) 12 : { 390 : [ 500 - ( 125 + 35 . 7 ) ] }
= 12 : {390 : [500 - (125 + 245)]}
= 12 : [390 : (500 - 370)]
= 12 : (390 : 130)
= 12 : 3 = 4.
b/ 12000 - ( 1500 . 2 + 1800 . 3 + 12 . 2 : 3 )
= 12000 - (3000 + 5400 + 24 : 3)
= 12000 - (8400 + 24 : 3)
= 12000 - (8400 + 8)
= 12000 - 8408
= 3592.
cho a R b =a*b/ a+b . Tinh gia tri bieu thuc cua : 13R7 - 12r4 . TINH gia tri cua bieu thuc tren ( 30 giay )
\(\frac{31}{20}\)đáp số đúng 1000000000000000000000000000000000000000000000000000% đó nha
h and kb nhé
bai 1 tinh gia tri cua bieu thuc 78 x m + 22 x m voi m =135
bai 2 tinh gia tri cua bieu thuc 78 x m + 42 x m -20 x m voi m =1035
bai 3 cho bieu thuc B = 119 x n - n x 9 bieu thuc B co gia tri bang 8470 khi n =............
Cho phan thuc B=(3\y+3)+(1\y-3)-(18\9-y2)
a)Tim dieu kien cua y de gia tri cua bieu thuc B duoc xac dinh
b)Rut gon bieu thuc B
c)Tinh gia tri cua B de B co gia tri nguyen
tinh gia tri cua bieu thuc 1+2 ( 25 + 9 ) - 4^3 =
\(1+2\left(25+9\right)-4^3=1+2\cdot34-64=5\)
1+2(25+9)−43=1+2⋅34−64=
nhưng lam gì có phép nhân ở 1+2(25 + 9 )Cho x+y=2, tinh gia tri cua bieu thuc:
M=3(x^2+y^2)-(x^3+y^3)+1
Bai 2:Cho a+b=5,tinh gia tri bieu thuc:
M=3a^2-2a+3b^2-2b+6ab+100