document.write( "Question 1063998: 3 years ago a man is four times the age of the daughter. If the product of their ages is 430 what are their present ages? \n" ); document.write( "
Algebra.Com's Answer #679036 by addingup(3677)\"\" \"About 
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m-3 = 4(d-3)
\n" ); document.write( "m = 4(d-3)+3
\n" ); document.write( "m = 4d-12+3
\n" ); document.write( "m = 4d-9
\n" ); document.write( "and
\n" ); document.write( "m*d = 430 here substitute for m:
\n" ); document.write( "(4d-9)*d = 430
\n" ); document.write( "d^2*4-9d-430 = 0
\n" ); document.write( "Now this equation is in standard quadratic form ax^2+bx+c = 0, so let's work it, the quadratic formula is (-b+/- sqrt(b^2-4ac))/2a:
\n" ); document.write( "d = [-(-9)+sqrt((-9)^2-4)*4(-430)]/2*4
\n" ); document.write( "d = [-(-9)+sqrt(81+(-16)*(-430))]/2*4
\n" ); document.write( "d = [-(-9)+sqrt(81+6880)]/2*4
\n" ); document.write( "d = [-(-9)+sqrt6961]/2*4
\n" ); document.write( "d = (9+sqrt6961)/8 Now you would repeat the exercise to solve when b is negative.
\n" ); document.write( "But We're not looking for a negative number, so let's solve what we've got:
\n" ); document.write( "d = 11.55
\n" ); document.write( "---------------------------
\n" ); document.write( "Check:
\n" ); document.write( "father - 3 = 4(d-3)
\n" ); document.write( "f-3 = 4(11.55-3)
\n" ); document.write( "f-3 = 34.2
\n" ); document.write( "f = 37.2
\n" ); document.write( "the problem says f*d = 430
\n" ); document.write( "37.2*11.55 = 429.66 round it off, it's 430 Correct
\n" ); document.write( ":
\n" ); document.write( "John
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