IDNStudy.com, ang perpektong platform para sa mabilis at eksaktong mga sagot. Ang aming komunidad ay handang magbigay ng malalim at praktikal na mga solusyon sa lahat ng iyong mga katanungan.

how do I solve this expression "2x² + 3x = -8" by using the quadratic formula?

Sagot :

from the equation 2x²+3x+8=0,
let a=2; b=3; c=8
substitute the values in the quadratic formula .
the solution is in the attachment
View image Rhyckayen
[tex]2x^2 + 3x = -8\\\\2x^2 + 3x+8=0\\a=2 , \ \ b=3, \ \ c=8\\\\x_{1}=\frac{-b-\sqrt{b^2-4ac}}{2a}=\frac{-3-\sqrt{3^2-4 \cdot 2\cdot8 }}{2a}=\frac{-3-\sqrt{9-64}}{2 \cdot 2}=\frac{-3-\sqrt{-55}}{4}=\frac{-3-\sqrt{ 55}i}{4} \\\\x_{2}=\frac{-b+\sqrt{b^2-4ac}}{2a}==\frac{-3+\sqrt{9-64}}{2 \cdot 2}=\frac{-3+\sqrt{-55}}{4}=\frac{-3+\sqrt{ 55}i}{4}\\ \\Answer: \ If b^2-4ac < 0, \ then \ roots \ are \ imaginary \ (non-real) [/tex]