SOLUTION: 6. The following are system of linear equation in two variables, except. a. {{{system(x + y = 11, x - y = 4)}}} b. {{{system(-x = 5, y - 4y = 2 )}}} c. {{{system(x + 4

Algebra ->  Linear-equations -> SOLUTION: 6. The following are system of linear equation in two variables, except. a. {{{system(x + y = 11, x - y = 4)}}} b. {{{system(-x = 5, y - 4y = 2 )}}} c. {{{system(x + 4      Log On


   

Question 1190188: 6. The following are system of linear equation in two variables, except.
a. system%28x+%2B+y+=+11%2C++x+-+y+=+4%29
b. system%28-x+=+5%2C+y+-+4y+=+2+%29
c. system%28x+%2B+4+=+y%2C2x+-+2y+=+-8%29
d. system%28x+%2B+8y+=+8%2C3x+%2B+y+=+18%29
Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
An equation is said to be linear equation in two variables
if it is written in the form of ax + by = c, where a, b & c 
are real numbers and the coefficients of x and y, i.e 
a and b respectively, are not equal to zero.

a. system%28x+%2B+y+=+11%2C++x+-+y+=+4%29    
b. system%28-x+=+5%2C+y+-+4y+=+2+%29   
c. system%28x+%2B+4+=+y%2C2x+-+2y+=+-8%29    
d. system%28x+%2B+8y+=+8%2C3x+%2B+y+=+18%29

In the choice (b.),  there is no y in the first equation,
which means that -x = 5 is equivalent to -x + 0y = 5, which
means that the coefficient of y is equal to 0.  That means
that it cannot be a linear equation in two variables.

Also in the choice (b.), there in no x in the second equation,
which means that y - 4y = 2, or -3y = 2 is equivalent to
0x - 3y = 2, which means that the coefficient of x is equal
to 0.  That is further reason that it cannot be a linear
equation in two variables.

Edwin