Answer:
a=5, a=-2.5
Step-by-step explanation:
Given:
[tex]2 a^2 - 5 a - 25 = 0[/tex]
Solution:
[tex]a_{1,\:2}=\frac{-\left(-5\right)\pm \sqrt{\left(-5\right)^2-4\cdot \:2\left(-25\right)}}{2\cdot \:2}[/tex]
[tex]a_{1,\:2}=\frac{-\left(-5\right)\pm \:15}{2\cdot \:2}[/tex]
[tex]a_1=\frac{-\left(-5\right)+15}{2\cdot \:2},\:a_2=\frac{-\left(-5\right)-15}{2\cdot \:2}[/tex]
[tex]a=5,\:a=-2.5[/tex]
~Lenvy~