Question

Answer 1

a: Thay x=-2 vào A, ta được:

\(A=-5\cdot\left(-2\right)^3+1=-5\cdot\left(-8\right)+1=40+1=41\)

b: Khi y=-1 thì \(B=\left(-1\right)^2-3\cdot\left(-1\right)+1\)

=1+3+1

=5

c: Khi x=-1;y=3 thì \(C=\left(-1-3\right)^2\left\lbrack\left(-1\right)^2-3\right\rbrack\)

\(=\left(-4\right)^2\cdot\left(1-3\right)=-2\cdot16=-32\)

d: x=y

=>x-y=0

=>\(N=\left(3x^3+y^2-3\right)\cdot0=0\)

e: \(N=\frac{x^2+y^2+2xy}{x+y}=\frac{\left(x+y\right)^2}{x+y}=x+y\)

Khi x=1;y=-2/3 thì \(N=x+y=1-\frac23=\frac13\)