7/8 of an hour is 52.5 minutes. 3/10 of 52.5 minutes is 15.75 minutes. They spent 15.75 minutes warming up and cooling down.
1/5 (or 20%) of $1,200 is $240
$1,200 - $240 = $960
The cost of a $1,200 washing machine after a discount of 1/5 (20%) is $960
(d): y = mx+n
m = -2/3 ⇒ y = (-2/3)x +n
A(-4, 6) ∈ d ⇒ 6 = (-2/3)·(-4) +n ⇒ 6 = 8/3 +n ⇒
⇒ n = 6 - 8/3 ⇒ n = 10/3
Now, we have:
y = (-2/3)x +10/3
Answer: C.)The survey should include all music choices.
Step-by-step explanation: To be honest i'm not sure-.