I have my final exam coming up for math so I got some practice problems from my professor, and I can't figure these out to save my life. Can anyone show me how to do these?

6z^2 - 48z + 72

27b^2 + 6bx - 63b - 14x

This last one is has to be done by grouping, which I mildly understand.

10a^2 + 43a + 28

For this one, I multiplied a x b (10 x 28) and got 280, then I factored it out to 35, and 8.

Then I wrote it down as (10a^2 + 8a) + (35a + 28) then I don't know where to go from there.

Can anyone help me out here? I am horrible at math.
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firstly, its called factorising. second, i cant be arsed.
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