Write as a polynomial:
a) y^2(y+5)(y-3)
b) 2a^2(a-1)(3-a)

  a) y^4 +2y^3 -15y^2

  b) -2a^4 +8a^3 -6a^2

Step-by-step explanation:

It is convenient to multiply the binomials first. The distributive property applies.

a) y^2(y(y -3) +5(y -3)) = y^2(y^2 -3y +5y -15) = y^4 +2y^3 -15y^2

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b) 2a^2(a(3 -a) -1(3 -a)) = 2a^2(3a -a^2 -3 +a) = -2a^4 +8a^3 -6a^2