Question 73447
SOlve by substitution: 
b = -2c + 4-----------------------------eq1
2c + b = 4--------------------------------eq2

Substitute b=-2c+4 from eq1 into eq2 and we get:

2c-2c+4=4
0+4=4

This system of equations has no solution.  Why???????????????
Because b=-2c+4 and 2c+b=4 are the same, identical equation

Lets look at eq1
b=-2c+4  add 2c to both sides

b+2c=-2c+2c+4  collect like terms

b+2c=4 or 2c+b=4-----------------same as eq2


Hope this helps----ptaylor