Question

Which graph correctly solves the system of equations below? x2 + y2 = 25 y = x + 1

Answer 1

The first thing you should realize is what kind of functions you have:
x2 + y2 = 25
It is a circle of radius r = 5 units.
y = x + 1
It is a line of positive slope.
The solution is the cut points of both graphs.
Attached graphic and analytical solution.

Answer 2

we have
x2 + y2 = 25
y = x + 1

using a graph tool
see the attached figure

the solution are the points (3,4) and (-4,-3)