Question 15449
Given 10x^2 - 3x - 4 = 0
      10x^2 -8x + 5x - 4 = 0  
      2x(5x - 4) +  1(5x - 4) = 0
       (5x-4)(2x+1) = 0
 (I have written -3x as (-8x+5x)  then took 2x common from the first two terms and 1 common for the next two terms . In the next step I took 5x-4 as common)