Question

factorise : 3x² + 5a - 2​

Answer 1

Step-by-step explanation:

Method 1 (By cross method)

3x2+5x+2

=(3x+2)(x+1)

Method 2 (By grouping)

3x2+5x+2

=3x2+3x+2x+2

=3x(x+1)+2(x+1)

=(3x+2)(x+1)

Method 3 (By quadratic formula)

By quadratic formula,

x=−5±(−5)2–4(3)(2)√2(3)=−1 or −23Therefore 3x2+5x+2=3(x+23)(x+1)=(3x+2)(x+1).

Answer 2

$3 {x}^{2} + 5a - 2$

$3 {x}^{2} + (6 - 1)a - 2$

$3 {x}^{2} + 6a - a - 2$

$3x(x + 2a)$