It appears to me that several values for x would work in number 1. I don't know how to solve it. Sorry.
2. Factor fully by grouping: 5x2 + 15x +4x + 12
I'm not sure what "by grouping" means, but I can factor the quadratic for you.
First add 15x and 4x 5x2 + 19x + 12
This will factor to (5x + 4)(x + 3)
On what basis do you say that 2x + 7 = 0 ?
And if it were accurate, then x would equal –3.5 not +3.5.
If you can't explain those, then I have to call bogus on this one.