Yes, is subtraction, to get their "difference".
first off, let's convert the mixed fractions, to "improper", and then subtract.

Answer:
23
Step-by-step explanation:
we are given that angle NRQ is 78 degrees
we can see from the figure that the sum of the given angles is angle NRQ
so
(8x + 7) + (4x - 1) = 78
12x + 6 = 78
12x = 72
x = 6
Now, we have to find angle PRQ
replacing x with 6 in the equation of angle PRQ
PRQ = 4(6) - 1
PRQ = 23
Answer:
a. -2
b. s = 2 and y = -5
c. (2.5, -9)
d. -7x - 2
Step-by-step explanation:
a. In the image, I have used rise over run, which is -8/4 or -2.
b. slope formula is mx + b = y, where m is slope and b is the y-intercept. In the equation 2x - 5y = -10, 2 is the slope and -5 is the y-intercept.
c. Plug in all given numbers into an equation and the ones you do not have will be in the points you need it to be. Once you graph the equation you will receive (2.5, -9).
d. y = mx + b
5 = (-7)(-1) + b
5 = 7 + b
-2 = b
y = -7x - 2