Question

A negative charge Q1= -4 uC and a positive charge Q2= 10 uC arelocated on the axes of a coordinate system. Q1 is at a distance of.6 (left along the x axis) from point P, the origin of thecoordinate system. Q2 is at a distance of 0.8 m (up along the yaxis) from P.
What is the magnitude of the electric field point P? (I usedF=kQ1Q2/ r^2....I was wondering if you could tell me why this iswrong)
In what direction is the electric field at point P? pointing intowhich quadrant (I,II,III,IV)