The relationship between celsius (°c) and fahrenheit (°f) degrees of measuring temperature is linear. find an equation relating °c and °f if 10°c corresponds to 50°f and 30c corresponds to 86°f. use the equation to find the celsius measure of 20° f.

(10,50) (30,86)

slope = (86 - 50) / (30 - 10) = 36/20 = 1.8

y = mx + b

slope (m) = 1.8

(10,50) ... x = 10 and y = 50

now sub and find b, the y int

50 = 1.8 (10) + b

50 = 18 + b

50 - 18 = b

32 = b

ur equation is : y = 1.8x + 32

when fahrenheit is 20 ... y = 20

20 = 1.8x + 32

20 - 32 = 1.8x

-12 = 1.8x

-12/1.8 = x

-6.67 = x ... celsius would be - 6.67