Question

Use the quadratic formula to find the x-intercepts of the function. Round to the nearest tenth if necessary.
y = -2x2 + 5x - 1
A. {2.3, 0.2}
B. {2.2, -5.8}
C. {-9.2, -0.8}
D. no real solution

Answer 1

\[x=\frac{ -b \frac{ + }{ - } \sqrt{b^2 - 4ac}}{ 2a }\]

Answer 2

\[x=\frac{ -5\frac{ + }{ - } \sqrt{5^2 - 4(-2*-1)}}{ 2*(-2) }\]

Answer 3

\[x=\frac{ 5\frac{ + }{ - } \sqrt{17}}{ -4 }\]

Answer 4

So you have:
\[x=\frac{ 5+\sqrt{8} }{ -4 }\]
and
\[x=\frac{ 5-\sqrt{8} }{ -4 }\]
Then you need to simplify to get your answer.