How do I factor; x^2-15x+56=?

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Answer 1 · 2018-03-05T01:37:56

$x^{2} - 7 x - 8 x + 56 = ?$ $x^2-7x-8x+56=?$

For $x^{2} - 15 x + 56$ $x^2-15x+56$

it is gonna be like this:

$x^{2} - 7 x - 8 x + 56$ $x^2-7x-8x+56$

$= x (x - 7) - 8 (x - 7)$ $=x(x-7)-8(x-7)$

$= (x - 7) (x - 8)$ $=(x-7)(x-8)$

Then if

$x^{2} - 15 x + 56 = 0$ $x^2-15x+56 = 0$

$(x - 7) (x - 8) = 0$ $(x-7)(x-8)= 0$

So

$x - 7 = 0 \Rightarrow x = 7$ $x-7=0 => x=7$

$x - 8 = 0 \Rightarrow x = 8$ $x-8=0 => x=8$