Solve using the substitution method. Show your work. If the system has no solution or an infinite number of solutions, state this.
4a + 20b = 8
8a = -40b + 16

Question

Solve using the substitution method. Show your work. If the system has no solution or an infinite number of solutions, state this.
4a + 20b = 8
8a = -40b + 16

anonymous · Answer

Substitution means you substitute one variable in for another.  So in this case we can solve for a:   first equation:   a = (8-20b)/4

now SUBTITUTE that into the second equation:    8[(8-20b)/4] = -40b + 16
and solve for b.

hero · Answer

8a = -40b + 16
8a + 40b = 16
2(4a + 20b) = 16
4a + 20b = 16/2
4a + 20b = 8

Thus 4a + 20b = 8 is equivalent to 8a = -40b + 16, which means they are the same equation.

anonymous · Answer

Thanks tons! This substitution stuff is kicking my butt! I appreciate all the help!

hero · Answer

yw =]

hero · Answer

Substitution is just playing with math. I can show you a few tricks

anonymous · Answer

please!!

hero · Answer

We can go on vyew and I can show you.

anonymous · Answer

what is that?

hero · Answer

It's a site with an online whiteboard and chat amongst other things. Great for collaboration.

anonymous · Answer

ok. let me go look.

hero · Answer

Let me set it up. Give me a minute.

hero · Answer

http://vyew.com/room#/418625/Open_Study_Math