Question

Find the value of the following expressions of x=-2,y=3.9 a)x²+xy+y² b) x³+y³​

Answer 1

Answer:

a) (-2)²+(-2)(3.9)+(3.9)²

Step-by-step explanation:

=4+7.8+15.2=27

b) (-2)³+(3.9)³

=(-8)+59.319

=51.319

Answer 2

Answer:

Now, (x+ y)3 – (x3 + y3) = (x + y) – (x + y)(x2– xy + y2)

[using identity, a3 + b3 = (a + b)(a2 -ab+ b2)] = (x+ y)[(x+ y)2 -(x2 -xy+ y2)]

= (x+ y)(x2+ y2+ 2xy- x2+ xy- y2)

[using identity, (a + b)2 = a2 + b2 + 2 ab)]

= (x + y) (3xy)

Hence, one of the factor of given polynomial is 3xy.