The expression for number of hours is: C. (3.39 × 10^7) ÷ (3.6 × 10^4)

The equations with no solutions are : A,B and C.

**Step-by-step explanation:**

The formula for time is distance divided by speed.

The distance given is 3.39 × 10⁷ miles.

The speed given is 3.6 × 10⁴ miles/hour

The time in hours will be = (3.39 × 10⁷ ÷3.6 × 10⁴) =941.67 hours

B.

Test to see if the equations have solutions;

(3x+4y=5)--------multiply by 6

(6x+8y=10 )-------multiply by 3

18x+24y=30

18x+24y=30 --------performing subtraction will give a zero on both sides. No solution.

The same to option B,and C.

For option D;

3x+6y=1

x+y=0 -------this can be written as x= -y

Sustitute x=-y in the first equation

3(-y) +6y =1

-3y+6y=1

3y=1

y=1/3

But x+y=0

Hence;

x+1/3=0

x=-1/3

solution ( -1/3, 1/3)

**Lean More**

Formula for speed:brainly.com/question/8311838

Solving inequalities:brainly.com/question/11213549

Keywords: distance, average speed, time, equations, solutions

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