You would solve this by finding m and b, and then the full equation.
This problem is slope intercept. m is the slope, b is the y-intercept.
The full equation is y = mx + b.
To find the y-intercept, or b, simply find where the line crosses the y-axis, which in this case, is 4. So b is 4.
To find the slope, or m, we will use rise/run. Up and right is positive, down and left is negative. Let's find two perfect points. (-4,3) and (0,4). Count how many units you rise (up), and run (right). I counted 7 up and 4 right. So 7/4 is m.
Now let's put it all in the equation. y = mx + b. You'll have y = 7/4x + 4.
Hope this helped!