\(x^2+2x-15\)
\(=x^2+5x-3x-15\)
\(=x\left(x+5\right)-3\left(x+5\right)\)
\(=\left(x+5\right)\left(x-3\right)\)
x2 + 2x - 15
= x2 + 5x - 3x - 15
= x.(x+5) - 3.(x+5)
= (x+5).(x-3)
x^2+2x-15=x^2+5x-3x-15
=x(x+5)-3(x+5)=(x-3)(x+5)
\(x^2+2x-15\)
\(=x^2+5x-3x-15\)
\(=x\left(x+5\right)-3\left(x+5\right)\)
\(=\left(x-3\right)\left(x+5\right)\)
x2 +2x - 15
= x2 - 3x + 5x -15
= x .( x - 3 ) + ( x - 3 )
= ( x + 5 ).( x - 3 )