Answer: 
<u>Step-by-step explanation:</u>

NOTE: The sign between 4x and 7 is missing in the question you posted. I assumed it was 4x + 7 in order to solve the equation.
Answer:
The system of equations has a one unique solution
Step-by-step explanation:
To quickly determine the number of solutions of a linear system of equations, we need to express each of the equations in slope-intercept form, so we can compare their slopes, and decide:
1) if they intersect at a unique point (when the slopes are different) thus giving a one solution, or
2) if the slopes have the exact same value giving parallel lines (with no intersections, and the y-intercept is different so there is no solution), or
3) if there is an infinite number of solutions (both lines are exactly the same, that is same slope and same y-intercept)
So we write them in slope -intercept form:
First equation:

second equation:

So we see that their slopes are different (for the first one slope = -6, and for the second one slope= -3/2) and then the lines must intercept in a one unique point. Therefore the system of equations has a one unique solution.
Answer:
9 is c
10 is b
i think the last one is a but not too sure
Step-by-step explanation:
Answer: x = 4
Step-by-step explanation:
An odd number of negative factors will give you a negative.