Given that the image of the first-order function y = KX + B passes through the point (- 2,5) and intersects with the y-axis at the point P, the line y = - 12x + 3 intersects with the y-axis at the point Q, and the point q is exactly symmetric with the point P about the x-axis, the expression of the first-order function is obtained

Given that the image of the first-order function y = KX + B passes through the point (- 2,5) and intersects with the y-axis at the point P, the line y = - 12x + 3 intersects with the y-axis at the point Q, and the point q is exactly symmetric with the point P about the x-axis, the expression of the first-order function is obtained

From the meaning of the question, we can get that the coordinates of point q are (0, 3), and the coordinates of point P are (0, - 3). Substituting (0, - 3), (- 2, 5) into the first-order function y = KX + B, we can get B = - 3 − 2K + B = 5, and the solution is b = - 3, k = - 4. So the expression of this first-order function is y = - 4x-3