SAT数学真题精选1. If 2 x + 3 = 9, what is the value of 4 x 3 ?(A) 5 (B) 9 (C) 15 (D) 18 (E) 212. If 4(t + u) + 3 = 19, then t + u = ?(A) 3 (B) 4 (C) 5 (D) 6 (E) 73. In the xy-coordinate (坐标) plane above, the line contains the points (0,0) and (1,2). If line M (not shown) contains the point (0,0) and is perpendicular （垂直） to L, what is an equation of M?(A) y = -1/2 x (B) y = -1/2 x + 1 (C) y = - x (D) y = - x +
