4.2x - 1.4y = 2.1
-1.4y = -4.2x + 2.1
y = (-4.2/-1.4)x + 2.1/-1.4
y = 3x - 1.5 <==
Because you have to go in the order of PEMDAS, parenthesis, exponents, multiplication, division, addition, and subtraction. From what you are saying, 'why you must simplify 3 to the second power first' it seems that you have no parenthesis, so you move onto what is next, which is exponents, in this case, 3 to the power of two.
Answer:
Please mark as brainliest.
The 3rd one. (where the round part of the graph is at 0, 0) because that is where the y axis meets