Which equation has a graph that lies entirely above the x-axis?
y = –(x + 7)2 + 7
y = (x – 7)2 – 7
y = (x – 7)2 + 7
y = (x – 7)2

The graph that lies entirely above x-axis is:

(Option 3 is correct )

Step-by-step explanation:

" The graph must lie entirely above x-axis means that there is no negative solution of the equation or no zero solution i.e. y must always attain positive value for any x "

the equation that satisfies this condition is:

Hence, option 3 is correct.

Because in

option 1:

for x=0 we have y= -42

Hence option 1 is incorrect some points will lie below x-axis.

option 2:

when x=7 y= -7

Hence some points will lie below x-axis.

Hence option 2 is incorrect.

option 4:

When x=7 y=0.

Hence this point lie on the x-axis.

Hence, option 4 is incorrect.

step-by-step explanation:

12: 00 p.m. to 7: 00 p.m. is a total of 7 hours.

4: 00 p.m. to 7: 00 p.m. is a total of 3 hours.

this means that from 4: 00 p.m to 7: 00 p.m. this represents 3/7 of what was lost from 12: 00 p.m. to 7: 00 p.m.

after knowing this, after doing 11,600 - 6,800 = 4,800

4,800 represents 3/7 of what was lost for 7 hours.

we then divide 4,800 by 3 which gets 1,600.

because we know that 1,600 represents 1/7 of how much water was lost, we just have to multiply by 7, which gets 11,200.   after adding 11,200 to how much water was left at 7: 00 p.m. which was 6,800. 11,200 + 6,800 = 18,000

this means that the pool originally had 18,000 gallons in the pool.

you can also check your work by doing 18,000 - 4(1600), which becomes           1800 - 6400 which gets you 11,600.