Question

use any method that you chose to find the point of interesection (x,y) for the following system of equationsx + y = 7y = -2x + 12

Answer 1

Let's solve the first equation for x:

x + y = 7 ------------------------------------------------------------------------------ Equation 1

x = 7 - y ------------------------------------------------------------------------------ Equation 1A

Now, we substitute Equation 1A into Equation 2 and solve for y:

** This means that we put what ever is x equal to in Equation 1A into the "x" of Equation 2. Then we multiply it out and do algebra to solve for y. SHOWN BELOW: **

y = -2x + 12 ----------------------------------------------------------------------- Equation 2

y = -2(7 - y) + 12

y = -14 +2y + 12

14 - 12 = 2y - y

y = 2

Equaton 1 was:

x + y = 7

We know y = 2, so substituting, we can solve for x:

x + y = 7

x + 2 = 7

x = 7 - 2

x = 5