SOLUTION: For the following system, use the second equation to make a substitution for y in the first equation. 2x + y = 6 y = 3x + 4 What is the resulting equation?

Algebra ->  Expressions-with-variables -> SOLUTION: For the following system, use the second equation to make a substitution for y in the first equation. 2x + y = 6 y = 3x + 4 What is the resulting equation?       Log On


   

Question 555080: For the following system, use the second equation to make a substitution for y in the first equation.
2x + y = 6
y = 3x + 4
What is the resulting equation?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
(1) +2x+%2B+y+=+6+
(2) +y+=+3x+%2B+4+
-------------
(1) +2x+%2B+3x+%2B+4+=+6+
(1) +5x+%2B+4+=+6+
(1) +5x+=+2+
(1) +x+=+2%2F5+
and
(2) +y+=+3x+%2B+4+
(2) +y+=+3%2A%282%2F5%29+%2B+4+
(2) +y+=+6%2F5+%2B+20%2F5+
(2) +y+=+26%2F5+
(2/5,26/5)
check answer:
(1) +2x+%2B+y+=+6+
(1) +2%2A%282%2F5%29+%2B+26%2F5+=+6+
(1) +4%2F5+%2B+26%2F5+=+6+
(1) +4+%2B+26+=+30+
(1) +30+=+30+
-------------
(2) +y+=+3x+%2B+4+
(2) +26%2F5+=+3%2A%282%2F5%29+%2B+4+
(2) +26+=+6+%2B+4%2A5+
(2) +26+=+26+
OK