Answer:
What do you mean DUO?
Step-by-step explanation:
Let h be the numbers of hours, f be the one-time fee and c the cost charged. The equation is

Since you pay $15 per four, plus the fee. We can solve this equation for the fee:

If we plug c=195 and h=9, we have

The descriminant is b^2-4ac so for 26 it would be -5^2 - 4 (1) (7). The quadratic formula is -B plus or minus the square root of b squared minus 4ac over 2a
Answer:
x=21
Step-by-step explanation:
add 5 to both sides. it gives u 21
-1 / 7 = x
You need to combine the 2x and 5x then devise the 7x from -1