document.write( "Question 507472: it is a 4 digit number. the 2 digit is two times greater than the 3. the sum of all digits is three times than the last digit of the number. the product of the 3 and 4 digit is 12 times bigger than the ratio of the 2 to 3.? \n" ); document.write( "
Algebra.Com's Answer #340573 by ankor@dixie-net.com(22740) You can put this solution on YOUR website! Write an equation for each statement, simplify and substitute if possible: \n" ); document.write( ": \n" ); document.write( "It is a 4 digit number. \n" ); document.write( "a, b, c, d; are the digits \n" ); document.write( ": \n" ); document.write( "The 2nd digit is two times greater than the 3rd. \n" ); document.write( "b = 2c \n" ); document.write( ": \n" ); document.write( "the sum of all digits is three times than the last digit of the number. \n" ); document.write( "a + b + c + d = 3d \n" ); document.write( "a + b + c = 3d - d \n" ); document.write( "a + b + c = 2d \n" ); document.write( "substitute 2c for b \n" ); document.write( "a + 2c + c = 2d \n" ); document.write( "a + 3c = 2d \n" ); document.write( ": \n" ); document.write( "the product of the 3 and 4 digit is 12 times bigger than the ratio of the 2nd to 3rd.? \n" ); document.write( "c*d = 12( \n" ); document.write( "Replace b with 2c \n" ); document.write( "c*d = 12( \n" ); document.write( "Cancel c and we have \n" ); document.write( "c*d = 24 \n" ); document.write( "We have 4 unknowns and 3 equations, so we will have to make an logical guess \n" ); document.write( "c=3, d=8; seems logical (d has to be the larger factor) \n" ); document.write( "Go with that and using the 2nd equation we have: \n" ); document.write( "a + 3c = 2d \n" ); document.write( "a + 3(3) = 2(8) \n" ); document.write( "a + 9 = 16 \n" ); document.write( "a = 16 - 9 \n" ); document.write( "a = 7 \n" ); document.write( "and \n" ); document.write( "b = 2(3) \n" ); document.write( "b = 6 \n" ); document.write( ": \n" ); document.write( "Our number: 7638 \n" ); document.write( "; \n" ); document.write( ": \n" ); document.write( "Check this using a + b + c + d = 3d \n" ); document.write( "7 + 6 + 3 + 8 = 3(8) \n" ); document.write( "24 = 24 \n" ); document.write( " |