Which of these rules governs visual design ? a)line and texture, b) hierarchy, c) increased visual response, d)use of complementary colors

The rules that governs the visual design are line and texture. The answer is letter A. The line connects two points and can be used to help characterize shapes and create dimensions. Texture on the other hand refers to how a surface feels or is perceived to feel. 

substitute y = 2x - 4 to x + 2y = 12:

x + 2(2x - 4) = 12     use distributive property

x + (2)(2x) + () = 12

x + 4x - 8 = 12     add 8 to both sides

5x = 20     divide both sides by 5

x = 4

put the value of x to the first equation:

y = 2(4) - 4

y = 8 - 4

y = 4