In the xy-plane, line l and line k intersect at the point (16/5, 12/5). What is the slope of line l? (1)
The product of the slopes of line l and line k is –1. (2)
Line k passes through the origin. A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient. B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient. C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient. D. EACH statement ALONE is sufficient. E. Statements (1) and (2) TOGETHER are NOT sufficient. 这题选对了，想问一下各位的解题过程，我不是很确定是否K1*K2=-1是否代表两条直线垂直？谢谢 | 
