Solve 7x^2+3x+3>0

$$7 { x }^{ 2 } +3x+3 > 0$$

Solve for x

$$x\in \mathrm{R}$$

Steps Using the Quadratic Formula

To solve the inequality, factor the left hand side. Quadratic polynomial can be factored using the transformation ax^{2}+bx+c=a\left(x-x_{1}\right)\left(x-x_{2}\right), where x_{1} and x_{2} are the solutions of the quadratic equation ax^{2}+bx+c=0.

$$7x^{2}+3x+3=0$$

All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. Substitute 7 for a, 3 for b, and 3 for c in the quadratic formula.

$$x=\frac{-3±\sqrt{3^{2}-4\times 7\times 3}}{2\times 7}$$

Do the calculations.

$$x=\frac{-3±\sqrt{-75}}{14}$$

Since the square root of a negative number is not defined in the real field, there are no solutions. Expression 7x^{2}+3x+3 has the same sign for any x. To determine the sign, calculate the value of the expression for x=0.

$$7\times 0^{2}+3\times 0+3=3$$

The value of the expression 7x^{2}+3x+3 is always positive. Inequality holds for x\in \mathrm{R}.

$$x\in \mathrm{R}$$