Question

Solve using the quadratic formula. Approximate to the nearest tenth.
x^2+2x-15=0

Answer 1

\[x=\frac{ -b \pm \sqrt{b ^{2}-4ac} }{ 2a }\]
\[x=\frac{ -2 \pm \sqrt{2 ^{2}-4(1)(-15)} }{ 2(1) }\]
\[x=\frac{ -2 \pm \sqrt{4+60} }{ 2 }\]
\[x=\frac{ -2 \pm \sqrt{64} }{ 2 }\]
\[x=\frac{ -2 \pm 8 }{ 2 }\]
\[x=3,x=-5\]