Question 1018404
4D+6P=670

3D+4P=465

Multiply first equation by 3, the second by 4

12D+18P=2010

12D+16P=1860

Now subtract second from first.

2P=150

P=75

Substitute into first. 

4D+6(75)=670

4D+450=670

4D=220

D=55