Question

factorisation method by square root of 5x^2+x-4=0​

Answer 1

Step-by-step explanation:

${5x}^{2} + x - 4 \\ = {5x}^{2} + 5x - 4x - 4 = 0 \\ = 5x(x + 1) - 4(x + 1) = 0 \\ = (x + 1)(5x - 4) = 0 \\ = x + 1 = 0 \: or \: 5x - 4 = 0 \\ = x = - 1 \: \: or \: \: x = \frac{4}{5}$