Solve 5x2 = –45x.
Solve x2 = 14x – 49.
Solve x2 + 18 = –9x.
Solve 4x2 = 12x + 40.

Question

Solve 5x2 = –45x.
Solve x2 = 14x – 49.
Solve x2 + 18 = –9x. 
Solve 4x2 = 12x + 40.

pfenn1 · Answer

Have you tried any of these?  Is there one in particular that you are having trouble with?

pfenn1 · Answer

The first equation, you can factor 5x and then rearrange and solve for x.,

pfenn1 · Answer

The second equation can be rearranged into the form $$ax^2+bx+c=0$$  Then the expression on the left can be factored into two expressions (x+A)(x+B) where (A + B) = -14 and AB = 49.

pfenn1 · Answer

The third equation can be handled the same way but in this case (A + B) = 9 and AB = 18.  This is the general idea.