The answer is: [D]: " - x − 8y = 56 " .
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Explanation:
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The "standard form" is: "Ax + By = c" .
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Given: " Y = 1/8 x + 7 " ;
↔ "(1/8)x + 7 = y " ;
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Subtract "7" from each side of the equation; & subtract "y" from each side of the equation :
→ (1/8)x + 7 − 7 − y = y − 7 − y ;
to get:
→ (1/8)x − y = - 7 ;
Now, multiply EACH side of the equation by "-8" ; to get rid of the FRACTION (since we want the "standard form" equation in INTEGERS; and use "NEGATIVE 8" to get ride of the "-7" ; since the "negative 7" multiplied by a "negative integer" will result in a POSITIVE INTEGER ;
→ -8 * {(1/8)x − y } = -8* {-7} ;
To get:
→ " - x − 8y = 56 " .
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The answer is: [D]: " - x − 8y = 56 " .
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Note: This is in "standard form" ; that is; "Ax + By = C" ;
in which: " A = -1 ; B = -8 ; C = 56 " .
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