+33661 Look at the pairs of factors of 8 that multiply to give 8: they are the pairs (1, 8) and (2, 4)
Look at the pairs of factors of 9 that multiply to give 9: they are (1, 9) and (3, 3)
The factorisation of 8x2 + 6x -9 will be in the form (a*x + b)*(c*x - d) where (a, c) are either (1, 8) or (2, 4) and (b, d) are either (1, 9) or (3, 3). We must also have that b*c - a*d = 6.
It is not difficult to find the result by trial and error: (2x + 3)*(4x - 3) = 8x2 + 6x - 9
+33661 Look at the pairs of factors of 8 that multiply to give 8: they are the pairs (1, 8) and (2, 4)
Look at the pairs of factors of 9 that multiply to give 9: they are (1, 9) and (3, 3)
The factorisation of 8x2 + 6x -9 will be in the form (a*x + b)*(c*x - d) where (a, c) are either (1, 8) or (2, 4) and (b, d) are either (1, 9) or (3, 3). We must also have that b*c - a*d = 6.
It is not difficult to find the result by trial and error: (2x + 3)*(4x - 3) = 8x2 + 6x - 9
