What is the x-coordinate of the point where the lines x=4y−8 and 12x+y=11 intersect?

I like to work with the slope-intercept form of the line:

x=4y-8 �> y = (1/4)x + 2 (1)

12x+y=11 �> y = -12x + 11 (2)

At the point where they intersect the two y values must be equal, so set eq(1) = eq(2):

(1/4)x + 2 = -12x + 11

( (1/4) + (48/4))x = 9

(49/4)x = 9

Ans: x = 36/49

Check: Plug in x=36/49 to eq(1) and eq(2) to make sure they produce identical y values:

(1) y = (1/4)(36/49) + 2 = (9/49) + (98/49) = 107/49

(2) y = -12(36/49) + 11 = (-432/49) + (539/49) = 107/49 (they match)

look a the sides they are perpendicular

to find the perimeter of the rectangle this is the expression:

x-9+x-9+3x-4+3x-4=138

if we simplify it:

8x-26=138

remember, 138 is what it all adds up to

the length is 11.5cm

the width is 57.5cm

the area is 661.25cm^2

the answers might not be correct use at own risk