How do you factor $2x^2-x-3$ ?

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Answer 1 · 2017-07-11T14:45:58

$(2x-3)(x+1)$

$2x^2-x-3=(2x-3)(x+1)$

since it is $2x^2$
in one of the brackets there must be a $x$ with the coefficient 2
$(2x...)(x...)$

next think how 3, 2, 1 (coefficients of $x^2,x and x^0$ respectively) relate to each other (using addition and subtraction)
$3-2=1$

what makes 3 and 2 and 1? using multiplication
$3*1=3$
$2*1=2$

Now we have clearer idea on what to do
$(2x-3)(x+1)$
there you go

If you are having difficulties to factorise (provided that the equation is factorisable), don't frustrate. You just need more practices.

Answer 2 · 2017-07-11T14:47:35

$(x + 1)(2x - 3)$

$2x^2 - x - 3$

$= 2x^2 - 3x + 2x - 3$

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

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

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