\(x+y=2\\ \Rightarrow\left(x+y\right)^2=4\\ \Rightarrow x^2+2xy+y^2=4\\ \Rightarrow10+2xy=4\\ \Rightarrow2xy=-6\\ \Rightarrow xy=-3\)
Ta có :
\(x^3+y^3=\left(x+y\right)\left(x^2-xy+y^2\right)=2\left(10+3\right)=2\cdot13=26\)
=> KL : ....
x + y = 2
<=> y = 2 - x
x2 + y2 = 10
<=> x2 + (2 - x)2 = 10
<=> x2 + x2 - 4x + 4 - 10 = 0
<=> 2x2 - 4x - 6 = 0
<=> 2x2 + 2x - 6x - 6 = 0
<=> 2x.(x + 1) - 6.(x + 1)
<=> (2x - 6)(x + 1) = 0
<=> 2x - 6 = 0 hoặc x + 1 =0
<=> x = 3 hoặc x = -1 <=> y = -1 hoặc y = 3
<=> x3 + y3 = 33 + (-13) = 24