The line l1 l_1\,l1 has equation 2y+6x+5=02y + 6x + 5 = 02y+6x+5=0 The line l2 l_2\,l2 has equation y=mx+7y = mx + 7y=mx+7, where m m\,m is a constant. Given that l1 l_1\,l1 and l2 l_2\,l2 are perpendicular.
Find the value of mmm.
260 exam-style questions on Edexcel A Level Maths Straight Line Graphs, covering 5.1 y = mx + c, 5.2 Equations of Straight Lines, 5.3 Parallel and Perpendicular Lines, 5.4 Length and Area, and 5.5 Modelling with Straight Lines. Each one has a worked solution and a mark scheme showing where the marks go.