document.write( "Question 665619: Ricardo's dog weighs 6 times as much as his cat. The total weight of his two pets is 98 pounds. How much does Ricardo's dog weigh? \n" ); document.write( "
Algebra.Com's Answer #413969 by DrBeeee(684)\"\" \"About 
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Let c = cat's weight
\n" ); document.write( "Let d = dog's weight
\n" ); document.write( "Since we have two unknowns we need two equations to solve the problem.
\n" ); document.write( "From the problem statement we have
\n" ); document.write( "(1) d = 6*c and
\n" ); document.write( "(2) d + c = 98
\n" ); document.write( "This is called a system of equations to find it in your text book. One of the simplist ways to solve this type of problem is by \"substitution\", wherein we solve one equation for one of the variable in terms of the other variable. Then replace that variable in the second equation with the resulting expression. In your case you already have d in terms of c given by (1), so you merely replace d in (2) with (1) and get
\n" ); document.write( "(3) 6*c + c = 98, ok?
\n" ); document.write( "or
\n" ); document.write( "(4) 7*c = 98 or
\n" ); document.write( "(5) c = 98/7 or
\n" ); document.write( "(6) c = 14
\n" ); document.write( "Using (2) with c = 14 we get
\n" ); document.write( "(7) d + 14 = 98 or
\n" ); document.write( "(8) d = 98 - 14 or
\n" ); document.write( "(9) d = 84
\n" ); document.write( "Are these values correct? Let's check using (1).
\n" ); document.write( "Is (84 = 6*14)?
\n" ); document.write( "Is (84 = 84)? Yes
\n" ); document.write( "Answer: Ricardo's dog weights 84 pounds. \n" ); document.write( "
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