document.write( "Question 77823This question is from textbook Algebra
\n" ); document.write( ": I really need some help on substitution methods I have tried all the problems. I understood a the beginning, but then it got harder. The problem is y/2-x=1 and x+y+7=0. \n" ); document.write( "

Algebra.Com's Answer #55795 by Earlsdon(6294) $\"\"$ $\"About$

You can put this solution on YOUR website!
Solve by substitution:
\n" ); document.write( " $\"y%2F2+-+x+=+1\"$ Solve this one for x: $\"highlight%28x+=+y%2F2+-+1%29\"$ and substitute for x in the second equation.
\n" ); document.write( " $\"x%2By%2B7+=+0\"$
\n" ); document.write( " $\"%28y%2F2+-+1%29%2By%2B7+=+0\"$ Simplify by multiplying by 2 to clear the fraction.
\n" ); document.write( " $\"y-2%2B2y%2B14+=+0\"$ Combine like-terms.
\n" ); document.write( " $\"3y%2B12+=+0\"$ Subtract 12 from both sides.
\n" ); document.write( " $\"3y+=+-12\"$ Finally, divide both sides by 3.
\n" ); document.write( " $\"y+=+-4\"$
\n" ); document.write( "Now substitute this value of y into the highlighted equation above to find x.
\n" ); document.write( " $\"x+=+%28-4%29%2F2+-+1\"$
\n" ); document.write( " $\"x+=+-2-1\"$
\n" ); document.write( " $\"x+=+-3\"$
\n" ); document.write( "The solution is: (-3, -4)
\n" ); document.write( "Here's the graphic solution:
\n" ); document.write( " $\"graph%28300%2C200%2C-5%2C5%2C-8%2C5%2C2x%2B2%2C-x-7%29\"$ \n" ); document.write( "

\n" );