Question 25597
Let the Douglas Fir=x
Ponderosa pines=y
So the first equation ;
x+y=850
They paid 300 for Douglas Fir;
300x
They paid 225 for Ponderosa pine;
225y;
So equation 2;
300x+225y=217500
First solve the firsst equation for x;
x+y=850
x=850-y
Now subatitute that in the 2nd equation forx;
300(850-y)+225y=217500
255000-300y+225y=217500
-75y=217500-255000
-75y=-37500
y=500
Now plug that into the first equation to find x;
x+500=850
x=850-500
x=350
Hope you understand
=)