Question

Solve : 21x^2 = 4(2x + 1)

Answer 1

Answer:

${21x}^{2} = 4(2x + 1)$

${21x}^{2} = 8x + 4$

${21x}^{2} - 8x - 4 = 0$

${21x}^{2} - (14 - 6)x - 4 = 0$

${21x}^{2} - 14x + 6x - 4 = 0$

$7x(3x - 2) + 2(3x - 2) = 0$

$(7x + 2)(3x - 2) = 0$

$(7x + 2) = 0 \: \: and \: \: (3x - 2) = 0$

$7x = - 2 \: \: and \: \: 3x = 2$

x = -2/7 and x = 2/3

Ans. -2/7, 2/3

Hope it helps.