Solve the equation: 5x^3+30x^2+45x=0
x^4-4x^2+3=0
|2x-5|=11

For the first equation don't let the cube trip you up. simply factor out 5x because 5 goes into all three numbers evenly as does the x. so now your equation reads 5x(x²+6x+9)=0. now factor x²+6x+9 like you normally would. now you should have 3 possible roots. 5x=0, x+3=0, and x+3=0. once you solve for x you should have x=0 and x=-3.

for the second one its a little trickier. we cant factor out the way we did in number one so you try to get all the x's to one side. ⇒ x^4-4x²=-3. now you can factor x² out to get x²(x²-4)=-3. now solve for x!! x²=-3 and x²-4=-3. you get x=√-3, x=1 and x=-1 

for the last one your going to solve the original version of the problem (2x-5=11) and the negated version of the problem. (-2x+5=11) all you're doing is solving for x. you should get x=-3 and x=8

21, i'm pretty sure it's right lol