Answer:
-0.8
Step-by-step explanation:
First move the variable terms to one side of the equal sign. I always move the smallest to the largest.
[tex]1.5a + 6 = 9a + 12 \\ - 1.5a \: \: \: \: \: \: \: \: \ \: - 1.5a[/tex]
Solve and move the constants to opposite side. I'm going to subtract 12 from both sides.
[tex] 6 = 7.5a + 12 \\ - 12 \: \: - 12[/tex]
Now solve for a by dividing both sides by 7.5
[tex] \frac{ - 6}{7.5} = \frac{7.5a}{7.5} [/tex]
[tex]a = - 0.8[/tex]