Subtract the coefficient of x times x from both sides. For example, if your slope-intercept form equation is y = -4/7x + 2, subtract -4/7x from both sides of the equation to get 4/7x + y = 2.
Subtract the y-intercept, the number without a coefficient, from both sides. In this example, subtract 2 from both sides to get 4/7x + y - 2 = 0.
Multiply each term by the denominator of the x-coefficient, if any, to complete the conversion to general form. In this example, the x-coefficient equals 4/7, so 7 is the denominator. Therefore, multiply 7 by 4/7x, y, 2 and 0 to get (4/7x)*7 + y*7 - 2*7 = 0*7, which simplifies to 4x + 7y - 14 = 0.