Posted by kaitlin on .
2x^2+x28=0
Solve by completing the square

math 
Reiny,
2x^2+x = 28
divide by 2
x^2 + x/2 = 14
add 1/16 to both sides
x^2 + x/2 + 1/16 = 14 + 1/16
x+1/4)^2 = 225/16
x + 1/4 = ± 15/4
x = 1/4 ± 15/4 = 7/2 or 4