To solve, your equation would be 2x - 2 >/= 8. You add 2 to both sides, getting 2x >/= 10. Then divide by two on both sides, your answer would be x >/= 5. (x is greater than or equal to 5).
ANSWER
Find out the how much fluid should be drained and replaced with pure antifreeze so that the new mixture is 60% antifreeze .
To proof
let us assume that the fluid should be drained and replaced with pure antifreeze be x .
As given
A radiator contains 10 quarts of fluid, 30% of which is antifreeze.
Now write 30% in the decimal form

Now write 60% in the decimal form

After drained and replaced the fluid with pure antifreeze than the quantity becomes = ( 10 - x )
The quantity of antifreeze is

The fluid should be drained and replaced with pure antifreeze so that the new mixture is 60% antifreeze .
than the equation becomes

solyving
100x +300 - 30x = 600
70x = 300

x = 4.28 quarts (approx)
Hence 4.28 quarts (approx) fluid should be drained and replaced with pure antifreeze so that the new mixture is 60% antifreeze .
Therefore the option (c.) is correct .
PYTHOGOROS THEROEM :-
ITS LIKE:- AC² = AB² + BC²