Pretty sure it’s D but if it is not then I don’t know
The most familiar case is that where you see a " + " sign between two numbers; that's an indication to add the two numbers (or terms) together.
Also, the instruction, "sum up the following," is a command to find the sum of all the numbers that follow.
Answer:
4
Step-by-step explanation:
firstly you separate y
y=-x-1
which means that the slope is equal to -1
then you flip the slope so -1 over -1 which is equal 1