document.write( "Question 973432: Find an equation of the line through(-1, 2) and (3, 10) \n" ); document.write( "

Algebra.Com's Answer #595627 by Boreal(15235) $\"\"$ $\"About$

You can put this solution on YOUR website!
First find the slope, which is the difference between the xs and the ys going in the same direction.\r
\n" ); document.write( "\n" ); document.write( "(10-2)= difference in y, or 8
\n" ); document.write( "3-(-1)=4, difference in x\r
\n" ); document.write( "\n" ); document.write( "slope is y/x, and that is (8/4)=2\r
\n" ); document.write( "\n" ); document.write( "Now use point slope formula\r
\n" ); document.write( "\n" ); document.write( "y-y1=m (x-x1)
\n" ); document.write( "m is slope, and you may use either point. You will get the same answer.\r
\n" ); document.write( "\n" ); document.write( "y-10=2(x-3)
\n" ); document.write( "distribute
\n" ); document.write( "y-10=2x-6
\n" ); document.write( "add 10 to both sides
\n" ); document.write( "y=2x+4\r
\n" ); document.write( "\n" ); document.write( "Alternative is use y=mx+b where y is 10, m=2, x=3
\n" ); document.write( "10=2(3)+b
\n" ); document.write( "10=6+b
\n" ); document.write( "b=4
\n" ); document.write( "y=2x+4\r
\n" ); document.write( "\n" ); document.write( " $\"graph%28300%2C300%2C-10%2C10%2C-10%2C12%2C2x%2B4%29\"$ \n" ); document.write( "

\n" );