Answer:
3x² + x + 1
-3x² + x + 1
-54
Explanation:
there is nothing complicated to it. you just use the requested pertain on the whole expressions of the functions, and the result is then the new function.
so,
r(x) = 3x²
s(x) = x + 1
what do you think s + r is ?
it is simply
(s+r)(x) = 3x² + x + 1
done. that is really all there is to this.
now the next (but consider the sequence due to the sign)
(s-r)(x) = x + 1 - 3x² = -3x² + x + 1
and the third
(s×r)(x) = 3x²(x+1) = 3x³ + 3x²
so, for x=-3
(s×r)(-3) = 3×(-3)³ + 3×(-3)²
remember, an even power of a negative number gives a positive result, an uneven power of a negative number gives a negative result.
(s×r)(x) = 3×-27 + 3×9 = -81 + 27 = -54