Answer:
<em>The values are a=6, b=8</em>
Step-by-step explanation:
<u>System of Equations</u>
We are given the system of equations:
ax - by = 4
bx - ay = 10
And it's known the solutions are: x=2, y=1.
Plugging in the solutions:
2a - b = 4 [1]
2b - a = 10 [2]
Now we have to solve the system above. Multiply [1] by 2:
4a - 2b = 8
Now we add with [2]:
3a = 18
a = 18/3 = 6
a = 6
From [2]:
2b - 6 = 10
2b = 16
b = 16/2 = 8
b = 8
The values are a=6, b=8
The next term is 1.4 larger than the one before it, so the appropriate choice is

_____
However, the description

also correctly describes the relationship between a1 and a2, for example. While this equation is technically correct, it is less useful to work with, so is probably not the expected answer.
First of all, you have to manipulate the equation into the standard

form. You can simplify the 1's on both sides and you have

This means that your coefficients are

And since the solving formula is

Plugging your values yields
