The answer is b
i think , im not sure
So to find the x vertex u have to apply the formula x= -b/2a so it will be
x= -(-4)/2(1)
x= 4/2
x= 2
and to find the y vertex u just substitute the x value into the original equation so it will be
y= (2)^2-4(2)+1
y= 4-8+1
y= -3
so the coordinates of the vertex are (2,-3)
The formula can be written in the form ...
... T = (original temperature) + x·(change in temperature each minute)
The problem statement gives you the original temperature (21 °C) and tells you the temperature after 12 minutes. You have to use that information to figure out the change in temperature each minute.
The change in temperature in 12 minutes is (75 °C) - (21 °C) = 54 °C. That is the change in 12 minutes, so the change in 1 minute will be 1/12 of that:
... 54/12 = 4.5
Using this value in the equation for T, we have
... T = 21 + 4.5x
Answer:
x > 15
Step-by-step explanation:
simplify both sides of the inequality
2x + 9 > 39
subtract 9 from both sides
2x + 9 - 9 > 39 -9
2x > 30
divide both sides by 2
2x/2 > 30/2
x > 15
