1) 0×1.8+32=32
2) x×1.8+32=212
1.8x+32-32=212-32
1.8x=180
1.8x÷1.8=180÷1.8
x = 100
3)a) f (x)=1.8x+32
b)f (5)= 1.8×5+32=9+32=41
c) 1.8x+32=5
1.8x= -27
x= -27÷1.8
x= -15
d) 10°Celsius valent 50° Fahrenheit
4) f (x)=1.8x+32
f (x)-32=1.8x
(f (x) -32)÷1.8=x
donc g (x) = (x-32)÷1.8
