You can put this solution on YOUR website! The slope intercept form of the equation of a line is:
Y = M*X + B where M is the slope of the line and B is the Y intercept (the value of Y when the line crosses the X-axis).
In this case we have a line of the form 10 = K*X + 7 which is already in slope intercept form with K being the slope of the line. So, for the line to have a slope of 3, K must have the value 3.
The equation of the line with slope 3 then becomes 10 = 3*X + 7.