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Find four solutions for the equation 3x + 5y = 15.
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\n" ); document.write( "You get to pick any points you want so make it easy on yourself. Because this is in standard form, (Ax+By=C), the x and y intercepts are easiest to solve for.
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\n" ); document.write( "Let x=0 and solve for y (y-intercept)
\n" ); document.write( "3(0)+5y=15
\n" ); document.write( "0+5y=15
\n" ); document.write( "5y=15
\n" ); document.write( "5y/5=15/5
\n" ); document.write( "y=3
\n" ); document.write( "One solution is: (0,3)
\n" ); document.write( ":
\n" ); document.write( "Let y=0 and solve for x. (x intercept)
\n" ); document.write( "3x+5(0)=15
\n" ); document.write( "3x+0=15
\n" ); document.write( "3x=15
\n" ); document.write( "3x/3=15/3
\n" ); document.write( "x=5
\n" ); document.write( "Your second solution is (5,0)
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\n" ); document.write( "The next two points, I'm going to pick are letting x=-10 and x=10. I know that they will work out to be whole numbers, it takes practice to find the easiest points.
\n" ); document.write( "Let x=-10 and solve for y.
\n" ); document.write( "3(-10)+5y=15
\n" ); document.write( "-30+5y=15
\n" ); document.write( "30-30+5y=15+30
\n" ); document.write( "5y=45
\n" ); document.write( "5y/5=45/5
\n" ); document.write( "y=9
\n" ); document.write( "Your third solution is: (-10,9)
\n" ); document.write( ":
\n" ); document.write( "Let x=10 and solve for y.
\n" ); document.write( " 3(10)+5y=15
\n" ); document.write( "30+5y=15
\n" ); document.write( "-30+30+5y=-30+15
\n" ); document.write( "5y=-15
\n" ); document.write( "5y/5=-15/5
\n" ); document.write( "y=-3
\n" ); document.write( "Your fourth solution is: (10,-3)
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\n" ); document.write( "Can you think of any others??? (Pick x's that are divisible by 5 to get whole numbers.)
\n" ); document.write( "Happy Calculating!!!! \n" ); document.write( "