The temperature in Toronto at noon during a winter day measured 4°C. The temperature started dropping 2° every hour. Which inequality can be used to find the number of hours, x, after which the temperature will measure below -3°C?
Can you please check my answer?
4−2x<−3
4-2x < -3
looks good to me
check:
now --- 4°
after 1 hr --- 2°
after 2 hrs--- 0°
after 3 hrs--- -2°
after 4 hrs--- -4°
so between 3 and 4 hrs it will reach -3°
4-2x < -3
-2x < -7
x > 3 1/2
Yes, your inequality is correct. The inequality 4 - 2x < -3 can be used to find the number of hours, x, after which the temperature will measure below -3°C.
To check if your answer is correct, we need to analyze the situation and understand how the temperature changes over time.
The temperature starts at 4°C at noon and then drops 2°C every hour. We want to find the number of hours after which the temperature will measure below -3°C.
Let's set up the inequality by considering the change in temperature over time. The temperature at any given hour can be calculated by:
Temperature at a given hour = 4°C - 2°C × number of hours (x)
To find the number of hours after which the temperature will measure below -3°C, we need to find the value of x that makes the temperature less than -3°C:
4°C - 2°C × x < -3°C
Now, let's simplify the inequality:
4 - 2x < -3
To solve for x, let's isolate the variable:
-2x < -3 - 4
-2x < -7
To get rid of the negative sign in front of x, we divide both sides of the inequality by -2, remembering to reverse the inequality sign when dividing by a negative number:
x > -7 / -2
x > 7/2
Therefore, the correct inequality that can be used to find the number of hours, x, after which the temperature will measure below -3°C is:
x > 7/2
In conclusion, the answer you provided, 4 - 2x < -3, is incorrect. The correct inequality is x > 7/2.