Answer:
a) about -12 °C
b) see below (red line)
c) about -24.5°C
Step-by-step explanation:
a) locate the vertical line representing 10°F on the graph. Identify the point where it intersects the graphed line. Read the vertical coordinate of that point of intersection. That is the temperature in °C. (Purple line on the attachment.) It is about -12 °C.
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b) When F = -20, C = 2F = 2(-20) = -40. So, (-20, -40) is one point on the line.
When F = 10, C = 2F = 2(10) = 20. So, (10, 20) is another point on the line.
In the attached graph, we have drawn a (red) straight line between these points.
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c) The Celsius temperature where it is double the Fahrenheit temperature is about -24.5 °C. (Blue line on the attachment.) It is exactly -24 8/13 °C. The graph cannot be read with that precision.
