Question

Solve:
4y2 + 12y + 9 = 0

Answer 1

that answer is showin up

Answer 2

\[\Large y = \frac{-b\pm\sqrt{b^2-4ac}}{2a}\]


\[\Large y = \frac{-(12)\pm\sqrt{(12)^2-4(4)(9)}}{2(4)}\]


\[\Large y = \frac{-12\pm\sqrt{144-(144)}}{8}\]


\[\Large y = \frac{-12\pm\sqrt{0}}{8}\]


\[\Large y = \frac{-12+\sqrt{0}}{8} \ \text{or} \ y = \frac{-12-\sqrt{0}}{8}\]


\[\Large y = \frac{-12+0}{8} \ \text{or} \ y = \frac{-12-0}{8}\]


\[\Large y = \frac{-12}{8} \ \text{or} \ y = \frac{-12}{8}\]


\[\Large y = -\frac{3}{2} \ \text{or} \ y = -\frac{3}{2}\]



So the only solution is \[\Large y = -\frac{3}{2}\]

Answer 3

you can also get benefit of some special formulas...

we know that a^2 + 2ab + b^2 =(a+b)^2
so
4y2 + 12y + 9 = 0
(2y)^2 +2(y)(3) + 3^2 =0
(2y+3)^2 =0

2y=-3
y=-3/2

Answer 4

@hoblos solution is much more impressive