Q. A line with a slope of −7 passes through the points (−7,−4) and (−9,f). What is the value of f?f = ____
Use Slope Formula: To find the value of f, we can use the slope formula, which is (change in y)/(change in x)=slope. We know the slope is −7, and we have the coordinates of one point (−7,−4) and the x-coordinate of the second point (−9). We can set up the equation using the known slope and the coordinates of the first point.
Set Up Equation: Let's denote the coordinates of the first point as (x1,y1)=(−7,−4) and the coordinates of the second point as (x2,y2)=(−9,f). The slope formula is x2−x1y2−y1=slope. Plugging in the known values, we get −9−(−7)f−(−4)=−7.
Simplify Equation: Simplify the equation: (f+4)/(−9+7)=−7. This simplifies to (f+4)/(−2)=−7.
Multiply Both Sides: To find f, we multiply both sides of the equation by −2: f+4=−7×−2.
Calculate Right Side: Calculate the right side of the equation: f+4=14.
Subtract 4: Subtract 4 from both sides to solve for f: f=14−4.
Calculate Final Value: Calculate the final value of f: f=10.
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