The answer is: " y = -15x + 104 " .
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y = mx + b ;
m = -15
y = -15x + b
When x = 7 ; y = -1 ;
-1 = -15(7) + b
-1 = -105 + b ;
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Solve for "b"
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-1 = -105 + b ; ↔ - 105 + b = -1 ;
↔ b − 105 = -1
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Add "105" to each side of the equation:
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b − 105 + 105 = -1 + 105 ;
b = 104
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y = mx + b ; → y = -15x + 104 .
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