Final answer:
To solve each equation for y, isolate y on one side of the equation. Subtract or add the necessary terms to accomplish that. Then, simplify the equation and express y in terms of x.
Step-by-step explanation:
To solve each equation for y, we need to isolate y on one side of the equation. Let's solve each equation step-by-step:
A. 3x - y = 16:
To isolate y, we can subtract 3x from both sides of the equation:
3x - y - 3x = 16 - 3x
-y = -3x + 16
Now, we can multiply both sides of the equation by -1 to make y positive:
y = 3x - 16
B. x + 4y = -31:
To isolate y, we can subtract x from both sides of the equation:
x + 4y - x = -31 - x
4y = -31 - x
Now, divide both sides of the equation by 4 to get y by itself:
y = (-31 - x) / 4
C. -5x - 9y = 23:
To isolate y, we can subtract -5x from both sides of the equation:
-5x - 9y + 5x = 23 - 5x
-9y = 23 - 5x
Now, divide both sides of the equation by -9 to get y by itself:
y = (23 - 5x) / -9