Answer:
1) x ≤ 2 or x ≥ 5
2) -6 < x < 2
Step-by-step explanation:
1) We have x^2 - 7x + 10, so let's factor this as if this were a regular equation:
x^2 - 7x + 10 = (x - 2)(x - 5)
So, we now have (x - 2)(x - 5) ≥ 0
Let's imagine this as a graph (see attachment). Notice that the only place that is above the number line is considered greater than 0, and that's when x ≤ 2 or x ≥ 5 (the shaded region).
2) Again, we have x^2 + 4x - 12, so factor this as if this were a regular equation:
x^2 + 4x - 12 = (x + 6)(x - 2)
So now we have (x + 6)(x - 2) < 0
Now imagine this as a graph again (see second attachment). Notice that the only place that is below 0 (< 0) is when -6 < x < 2 (the shaded region).
Hope this helps!
-3+2x = -6 (negative and negative changes to positive (+))
2x = -6+3
2x = -3
x = -3/2
Answer:
Step-by-step explanation:
1) Price of 8 pack of toothbrushes = $ 18.12
Price he paid after using coupon = 18.12 - 3 = $ 15.12
Unit rate = Price he paid ÷ number of toothbrushes
= 15.12 ÷ 8
= $ 1.89
2) 0.5 hours = 30 minutes
Duration of guitar class on Monday = 30 minutes
Duration of guitar class on Tuesday = 1.5 hours = 1 hr 30 min
Duration of guitar class on Thursday = 2 hrs
Total duration = 30 min + 1hr 30 min + 2 hrs
= 4 hrs
Amount paid for 4 hrs = $ 180
Rate per hour = 180 ÷ 4
= $ 45
Given that these are all regular, 4 is 173.7. 5 is 98.7. 6 is 90.8.