Factor.

1. 30y^3 - 50y

A: 10y(3y - 5y)

2. Factor a^2 - 5a^2 + 2a -10 by grouping.

A: ?

check by expanding your answer, you will see that the first one is wrong

you probably meant
a^3 - 5a^2 + 2a -10 , says by grouping, so do that ...

= a^2(a-5) + 2(a-5)
= (a-5)(a^2 + 2)

To factor the expression a^2 - 5a^2 + 2a -10 by grouping, we need to group the terms in pairs and find a common factor for each pair.

First, let's group the terms:
(a^2 - 5a^2) + (2a - 10)

Now, factor out the common factor from each group:
a^2(1 - 5) + 2(a - 5)

Simplifying further, we have:
a^2(-4) + 2(a - 5)

Now, we can factor out -4 and (a - 5) as the common factors:
-4(a^2 - 2(a - 5))

Therefore, the factored form of the expression a^2 - 5a^2 + 2a -10 by grouping is -4(a^2 - 2(a - 5)).