Standard form of a line:
Ax + By = C
where A is a positive integer, B is an integer and C is a constant.
10. y + 1 = x + 2
y + 1 - y = x + 2 - y subtracting y at both sides
1 = x + 2 - y
1 - 2 = x + 2 - y - 2 subtracting 2 at both sides
-1 = x - y
13. y - 4 = -(x - 1)
(y - 4)*(-1) = -(x - 1)*(-1) Multiplying by -1 at both sides
-y + 4 = x - 1
-y + 4 + y = x - 1 + y Adding y at both sides
4 = x - 1 + y
4 + 1 = x - 1 + y + 1 Adding 1 at both sides
5 = x + y
16. y - 10 = -2(x - 3)
(y - 10)/(-2) = -2(x - 3)/(-2) Dividing by -2 at both sides
y/-2 +5 = x - 3
2*(y/-2 +5) = 2*(x - 3) Multiplying by 2 at both sides
-y + 10 = 2x + 6
-y + 10 + y = 2x + 6 + y Adding y at both sides
10 = 2x + 6 + y
10 - 6 = 2x + 6 + y - 6 subtracting 6 at both sides
4 = 2x + y