math_dude16
Mar 13, 2009, 08:37 AM
Could someone please help me! This problem with elimination not SUBSITUTION:
Nn+ Nd= 50
5Nn+10Nd= 450
galactus
Mar 13, 2009, 01:16 PM
N is a constant and n and d are the variables.
Nn+Nd=50
5Nn+10Nd=450
Multiply the top equation by -5. See why? We have to find a number that eliminates a variable. In this case, -5+5=0. So, we have:
-5Nn-5Nd=-250
5Nn+10Nd=450
Add them:
5Nd=250
d=\frac{50}{N}
Now, you find n.