Respuesta :

Answer:

x=2

Step-by-step explanation:

PQ+QR=PR

=x^2+3+4+2x=15

=x^2+2x+7=15

=x^2+2x+7-15=0

=x^2+2x-8=0. (quadratic equation)

=(x+4)(x-2)=0. (factorise)

=x+4=0 or x-2=0

x=-4 or 2

we take x to be the positive value which is

x=2