document.write( "Question 1007101: Three times a first number decreased by a second number is 3.the first number increases by twice the second number is 15.find the numbers \n" ); document.write( "
Algebra.Com's Answer #623094 by addingup(3677)![]() ![]() You can put this solution on YOUR website! 3x-y= 3 \n" ); document.write( "x+2y= 15 Let's multiply both sides by 3: \n" ); document.write( "3x+6y= 45 Now subtract this equation from the first: \n" ); document.write( "----------------------------- \n" ); document.write( "3x-y= 3 \n" ); document.write( "- 3x-6y= -45 (watch your signs, you are subtracting so numbers turn negative) \n" ); document.write( "___ -7y= -42 \n" ); document.write( "____ y= 6 \n" ); document.write( "So we have that y, the second number, is 6. Now back to the top, to the first equation: \n" ); document.write( "-------------------------------- \n" ); document.write( "3x-y= 3 Using y= 6: \n" ); document.write( "3x-6= 3 \n" ); document.write( "3x= 9 \n" ); document.write( "x= 3 This is the first number \n" ); document.write( "---------------------------- \n" ); document.write( "Check: \n" ); document.write( "3(3)-6= 3 \n" ); document.write( "9-6= 3 OK, we got this correct \n" ); document.write( "3+2(6)= 15 \n" ); document.write( "3+12= 15 \n" ); document.write( "15=15 This one is also correct. We have the right answers. \n" ); document.write( " |