Answer:

Step-by-step explanation:





I used the following rules:


Let x be your first alloy
2/5x+7/10(30-x)=1/2(30)
4x+210-7x=150
3x=60
x=20
So, you need 20 lbs of the first alloy, and 10 parts of the second to make 30 lbs of half iron and half silver alloy!
THE SLOPE IS -2
if we have the coordinates of two points on a line, we can find the slope with this formula:

so the slope is

the answer is -2
good luck