document.write( "Question 1137780: Here is a tricky word problem that I hope I can get some help with from an expert here:
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document.write( "T varies jointly as r and Bsquared. When r=7 and B=6, T=1008. Find T when r is 10 and 8 is 12. \r
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document.write( "(T=4rB squared is not it)\r
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document.write( "Thank you. \n" );
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Algebra.Com's Answer #755665 by greenestamps(13200)![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "You say T = 4rB^2 \"is not it\". \n" ); document.write( "That's because that answer is a formula for calculating T from r and B; but the problem didn't ask for a formula. It asked for the new value of T given new values of r and B. \n" ); document.write( "You can get the answer by plugging the new values in the formula. \n" ); document.write( "However, since the problem only asks for the value of T with new values of r and B, there is no need to find a general formula. You can get the answer just by using the stated joint variation to see how the given value of T changes when the values of r and B change. \n" ); document.write( "The given value of r is 7; the new value of r is 10. Since T varies directly as r, the new value of r multiplies the given value of T by 10/7. \n" ); document.write( "The given value of B is 6; the new value of B is 12. Since T varies directly as the square of B, the new value of B multiplies the given value of T by (12/6)^2 = 2^2 = 4. \n" ); document.write( "So the new value of T is \n" ); document.write( " |