I'll help you but I;m not just going to give you the answer
Yes, is subtraction, to get their "difference".
first off, let's convert the mixed fractions, to "improper", and then subtract.

Answer:

Step-by-step explanation:
If two lines are perpendicular, they create 4 90° angles. Meaning, in this case, that m<DBC = 90 and m<DBA = 90.
We're given that m<DBE = 2x - 1 and that m<CBE = 5x - 42.
The sum of angles DBE and CBE = m<DBC = 90°
We can add the two angles and set it equal to 90 to find x

To find out if they are parallel we need to see if the gradient is the same, to do this we need to get y in terms of x:
assuming the first equation is x+y+7=0
y=-x-7
and
y=x-3
The gradient is the coefficient of x (the number infront of x)
For equation 1 the gradient is -1, and for number 2 it is 1, therefore they are not parallel.
However to check if they are perpendicular we need to see if their gradients multiply to equal -1.
-1*1=-1 therefore they are perpendicular
Answer:
B
Step-by-step explanation:
Given a system of equations graphically, then the solution is at the point of intersection of the 2 equations.
As can be seen from the graph there is only 1 point of intersection, thus only one solution,