document.write( "Question 1068458: Suppose f(x) is a linear function such that f(-1/2) = -7 and f(1) = -3. What is f(-3)? Thank you!
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Algebra.Com's Answer #683668 by math_helper(2461)\"\" \"About 
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Linear function means the relation of f(x) to x has x raised to the first power.
\n" ); document.write( "Thus, we can write:
\n" ); document.write( " f(x) = mx+b
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\n" ); document.write( "f(-1/2) = -7 —> -7 = m*(-1/2) + b (1)
\n" ); document.write( "f(1) = -3 —> -3 = m*(1) + b (2)
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\n" ); document.write( "Subtract (2) from (1) to get one equation with just 'm':\r
\n" ); document.write( "\n" ); document.write( " -4 = -(3/2)m
\n" ); document.write( " m = 8/3
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\n" ); document.write( "Plug 8/3 in for 'm' in (1) (or (2)) and solve for 'b':
\n" ); document.write( " -7 = (8/3)(-1/2) +b
\n" ); document.write( " b = -17/3
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\n" ); document.write( "Now we have:
\n" ); document.write( " \"+f%28x%29+=+%288%2F3%29x+-+17%2F3+\"\r
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\n" ); document.write( "Just plug in x=-3 and you'll have the answer.
\n" ); document.write( "I got -41/3.
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