3D Cube Project, By Thanh Quotient

For this 3D cube project, i created a cube corner to graph my points to show my real 3D shape.
My original equation was x + y + Z = 3, i multiplied 2 variables by 0 per equation:
x(0) + y(0) + Z = 3, Z-intercept: (0,0,3)
x(0) + y + Z(0) = 3, Y-intercept: (0,3,0)
x + y(0) + Z(0) = 3, X-intercept: (3,0,0)
Once i had the intercepts, i was then able to substitute every intercept to fit my own corner, which is the only way to form a 3D model. My region of the whole 3D model was: (X,-Y,-Z)
Since i had all 3 intercepts, i then plugged it in, giving me:
(0,0,3) ---> (0,0,-3)
(0,3,0) ---> (0,-3,0)
(3,0,0) ---> (3,0,0)

now that i have the intercepts that suits my corner of (X,-Y,-Z) it allowed me to create a surface of a triangle that i made with yarn indicated in green.