Question

What should you multiply the first equation (top equation) by in order toeliminate the variable y when the two equations are added together?(x+2y = 513x - 4y - 8

Answer 1

Ok, we can see that the coeficient of "y" in the second ecuation is -4, so if we need to eliminate the variable y when the two equations are added together, we need to add 4 and -4 to eliminate this, so we are going to divide 4 by 2 to find the required value:

`x=(4)/(2)=2`

So, if we multiplicate the first equation by 2, when the two equations are added together the variable "y" is eliminated.