Three and four tenths
HOPE I HELPED!!!
Answer:
2
Step-by-step explanation:
the mean (average) change in gasoline in gallons per day = (25-11) gallons / 7 days
= 14/7 = 2 gallons per day
Answer: For the graph,
43. y=2.5x−4
45. y=−15x+3
47. y=12x+−94
Step-by-step explanation:
43.
Let's solve for x.
y=2.5x−4
Step 1: Flip the equation.
2.5x−4=y
Step 2: Add 4 to both sides.
2.5x−4+4=y+4
2.5x=y+4
Step 3: Divide both sides by 2.5.
2.5x2.5=y+42.5
x=0.4y+1.6
Answer:
x=0.4y+1.6
45.
Let's solve for x.
y+15x=3
Step 1: Add -y to both sides.
15x+y+−y=3+−y
15x=−y+3
Step 2: Divide both sides by 1/5.
15x15=−y+315
x=−5y+15
Answer:
x=−5y+15
47.
Let's solve for x.
2x−3=4y+6
Step 1: Add 3 to both sides.
2x−3+3=4y+6+3
2x=4y+9
Step 2: Divide both sides by 2.
2x2=4y+92
x=2y+92
Answer:
x=2y+92
Answer:
The best deal is the middle one.
Step-by-step explanation:
35.95 with a 20% discount.
You can do this the straight forward way. Take 20% 35.95
20/100 * 35.95 = 7.19
Now subtract this from 35.95
35.95 - 7.19 = 28.76
15/100 * 29.75 = 4.46
29.75 - 4.46 = 25.28
25% * 38.49 = 9.62
38.49 - 9.62 = 28.86
So, when verifying trig identities, a general rule is that you only want to manipulate one side of your equation. usually if you mess with both sides, you can get a little lost with the equation. the problems are created so that you only have to use one side.
cot²x - cot²x cos²x = cos²x
the first thing you can do here is factor a cot²x out of the left side of your equation:
cot²x (1 - cos²x) = cos²x
look inside the parentheses. you should recognize that as something you can make out of one of the pythagorean trig identities -- sin²x + cos²x = 1
to get this identity to match the inside of your parentheses, subtract cos²x:
sin²x = 1 - cos²x
so now you can substitute sin²x into your parentheses:
cot²x (1 - cos²x) = cos²x
cot²x (sin²x) = cos²x
recall that cot is the inverse of tan; tangent can be represented by (sin x/cos x) and cot is the reverse of that: (cos x/sin x)
(cos²x/sin²x)(sin²x) = cos²x
your sin²x's cancel out, as one is being divided and the other is being multiplied, and you're left with:
cos²x = cos²x