Rewrite the equation x + y + 3 = - 2x + 4y + 18 into standard form (ax + by = c)

A. x - y = 5

B. x - y = 15

C. 3x - 3y = 5

D. x + y = 5

Choice A is correct answer.

Step-by-step explanation:

Given equation is:

x+y+3 = - 2x+4y+18

Adding 2x to both sides of above equation, we get

2x+x+y+3 = 2x-2x+4y+18

3x+y+3 = 0+4y + 18

Adding - 4y to both sides of above equation, we get

3x+y+3 - 4y = 4y+18-4y

3x-3y+3 = 18

Adding - 3 to both sides of above equation, we get

3x-3y+3-3 = 18-3

3x-3y = 15

Taking 3 common to both sides of above equation, we get

3 (x-y) = 3 (5)

Hence, x-y = 5 where a = 1, b = - 1 and c = 5