I’ll mark you brainlist I’ll mark you brainlist I’ll mark you brainlist I’ll mark you brainlist I’ll mark you brainlist I’ll mark you brainlist I’ll mark you brainlist I’ll mark you brainlist I’ll mark you brainlist I’ll mark you brainlist

-1

Step-by-step explanation:

When a line is perpendicular to another line, it means that the line is going through the other line. So that means they have the opposite slope or the reciprocal of the first line and you change the sign to become opposite.

y=x-4 ---> find reciprocal of x

y=-1x-4

slope= -1

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.