Answer:
x + y = 12
Explanation:
Standard form is Ax+By=C
so the goal is to get the y and the x on the same side without and negatives or fractions on that side.
y - 8 = - (x - 4) first, start by simplifying
y - 8 = -x +4 next, because it is negative, we are going to add x to -x on the right side to get it to cancel out and we'll add x to y on the left side
x + y - 8 = 4 now we need to get rid of that eight so we'll add 8 to -8 so it cancels out and we'll add 8 to 4
x + y = 12 now it is in standard form