Solve an inequality. 4x ^ 2 + 12x + 9 is less than or equal to 0 4X ^ 2 + 12x + 9 less than or equal to 0

Solve an inequality. 4x ^ 2 + 12x + 9 is less than or equal to 0 4X ^ 2 + 12x + 9 less than or equal to 0

4X ^ 2 + 12x + 9 less than or equal to 0
(2x)^2+2*4x*3+3^2≤0
（2x+3)^2≤0
For any x, (2x + 3) ^ 2 ≥ 0
So there's only one 2x + 3 = 0
The solution is x = - 3 / 2
I hope I can help you_ ∩)O

If a ＜ 0, the solution set of inequality system: 12x + a ＞ 0, 4x + a ＜ 0 is

From the inequality group: 12x + a > 0,4x + a < 0
x＞-a/12 x＜-a/4
That is to compare the size of - A / 12 and - A / 4
Because a ＜ 0 - a ＞ 0 means - A / 4 ＞ - A / 12
Then the solution set is - A / 12 ＜ x ＜ - A / 4

-4X square + 12x

-4X square + 12x
4X square - 12x > 0
=>
4x(x - 3) >0
therefore
x> 0 and x-3 > 0
perhaps
x

Solving quadratic equation of one variable: 4x & # 178; - X-9
4x²-x-9 =0

x=﹙1±√1+4×4×9﹚/2×4=﹙1±√145﹚/8
x1=﹙1+√145﹚/8
x2=﹙1-√145﹚/8