P and W are twice-differentiable functions with P(7)=2(W(7)). The line y=9+2.5(x-7) is tangent to the graph of P at x=7. The line y=4.5+2(x-7) is tangento to the graph of WQ at x=7. Let m be a function such that m(x)=x(W(x)). Find m'(7).