Answer:
please see explanation
Step-by-step explanation:
[tex]10a {}^{2} + 4 = - 186 \\ 10a {}^{2} = - 186 - 4 \\ 10a {}^{2} = - 190 \\ divide \: bothsides \: by \: 10 \\ \frac{10a {}^{2} }{10} = \frac{ - 190}{10} \\ a { }^{2} = - 19 \\ square \: root \: bothsides \\ \sqrt{a {}^{2} } = \sqrt{ - 19} \\ a = - 1 \sqrt{19 } \\ a = + i \sqrt{19} \: or \: a = - i \sqrt{19} [/tex]
