The usual rules of addition and multiplication apply to complex numbers as well as to real numbers. The true statements are ...
- x + y = y + x . . . . . . . . . . . . . . . commutative property of addition
- (x × y) × z = x × (y × z) . . . . . . . . associative property of multiplication
- (x + y) + z = x + (y + z) . . . . . . . . associative property of addition
Answer:
150 * 0.27777777778 kg = 41.666666667 kg.
On the added picture you can see that graphs of functions

and

have two points of intersection. The x-coordinates of these points are the solutions of the equation

.
Hence, the approximate solutions are x=-1.9 and x=1.6.
Answer:
We want a polynomial of smallest degree with rational coefficients with zeros in
,
and -3. The last root gives us the factor (x+3). Hence, our polynomial is

where
is a polynomial with rational coefficients and roots
and
. The root
gives us a factor
, but in order to obtain rational coefficients we must consider the factor
.
An analogue idea works with
. For convenience write
. This gives the factor
. Hence,

Notice that
. So, in order to satisfy the last condition we divide by 3 the whole polynomial, without altering its roots. Finally, the wanted polynomial is

Step-by-step explanation:
We must have present that any polynomial it's determined by its roots up to a constant factor. But here we have irrational ones, in order to eliminate the irrational coefficients that a factor of the type
will introduce in the expression, we need to multiply by its conjugate
. Hence, we will obtain
that have rational coefficients. Finally, the last condition is given with the intention to fix the constant factor. Usually it is enough to evaluate in the point and obtain the necessary factor.