Answer:
-40 < t < 284
Step-by-step explanation:
The antifreeze protects the car between −40°C and 140°C.
Using t for temperature, the compound inequality of the Celsius temperature range is:
-40 < t < 140
The conversion formula is given to find degrees C in given degrees F. We can solve the formula for F, so we get degrees F in terms of degrees C.
C = (5/9)(F - 32) <------ conversion formula from deg F to deg C
Solve for F:
(9/5)C = F - 32
(9/5)C + 32 = F
F = (9/5)C + 32 <------ conversion formula from deg C to deg F
Now we convert -40 deg C to deg F using the formula we just derived.
F = (9/5)C + 32
F = (9/5)(-40) + 32
F = -72 + 32
F = -40
-40 deg C = -40 deg F
(This is not a mistake or a typo. -40 deg C really is the same as -40 deg F.)
Now we convert 140 deg C to deg F using the formula we just derived.
F = (9/5)C + 32
F = (9/5)(140) + 32
F = 252 + 32
F = 284
140 deg C = 284 deg F
Now we rewrite the compound inequality with Fahrenheit temperatures.
-40 < t < 284
