The factored form of 4m³ – 28m² – 120m is 4m(m – 10)(m + 3). The zeroes of the function would be m = 0, m = –3, and m = 10.

Step-by-step explanation:

I'll give this a shot.

4m³ – 28m² – 120m = 0 — The original expression

4m³ – 28m² – 120m — Did that 0 have any purpose? I just deleted it.

4(m³ – 7m² – 30m) — There's a common factor in here, 4. Let's pull that aside.

4m(m² – 7m – 30) — Actually, there's two common factors. The second one is m! Let's pull that out too!

To factor an expression, you have to break apart the middle term, so to speak. That's only possible if you can find two numbers whose product equals that of the outside terms and whose sum equals the middle term. Here, I'm just dealing with numbers and putting that variable aside.

–30 = 10 × –3

–30 = –10 × 3

–30 = –2 × 15

–30 = 2 × –15 — To solve for any potential factors, let's find all the numbers integers that multiply to –30

Now let's see which one adds up to –7!

15 – 2 = 13 — it's not this one

2 – 15 = –13 — nor this one

10 – 3 = 7 — we're pretty close! Let's switch that negative

3 – 10 = –7 — here we go! Here's our numbers!

4m[(m² – 10m) + (3m – 30)] — now we break apart the middle term. This is all multiplied by 4m, so that still encases everything with brackets.

4m[m(m – 10) + 3(m – 10)] — Factoring the two expressions

4m(m + 3)(m – 10) — simplifying to find our answer! Ta-da!