Solve the system of equations
x + 3y = 7
x - 3y = 1

(4, 1)

Step-by-step explanation:

Let's visualize what this system of equations is telling us: If we start at some number x and go up some amount (3y), we get to 7. If we go down that same amount, we get to 1. So x must be halfway between 1 and 7, which is 4. So the distance from x to 7 (and from 1 to x), must be 3. Since we already said the distance is 3y, we can set those two values equal with the equation 3y = 3, which means y = 1. So our solution must be x = 4, y = 1, which we could write as the ordered pair (4, 1).

point a is the center of this circle.

the ratio of the lengths of (ef/bc) and (ad/ih) is 2: 1.

step-by-step explanation:

step-by-step explanation:

∆abc has the points a(1, 7), b(-2, 2), and c(4, 2) as its vertices. formed with the point d(1, 2) as its third vertex, then ∆abd is triangle.