The first equation has no solution
The picture shows all the work I did, the reason I took a pic is because it is a little hard to explain by text, but I hope this helped you!
Distribute the .25 to get .25x + 1 - 3 = 28
Then simplify to get .25x - 2 = 28
Move the two to the right to get .25x = 30
Then divide to leave x: 30 / .25 = 120
X = 120
Answer: see proof below
<u>Step-by-step explanation:</u>
Use the Double Angle Identity: sin 2Ф = 2sinФ · cosФ
Use the Sum/Difference Identities:
sin(α + β) = sinα · cosβ + cosα · sinβ
cos(α - β) = cosα · cosβ + sinα · sinβ
Use the Unit circle to evaluate: sin45 = cos45 = √2/2
Use the Double Angle Identities: sin2Ф = 2sinФ · cosФ
Use the Pythagorean Identity: cos²Ф + sin²Ф = 1
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<u>Proof LHS → RHS</u>
LHS: 2sin(45 + 2A) · cos(45 - 2A)
Sum/Difference: 2 (sin45·cos2A + cos45·sin2A) (cos45·cos2A + sin45·sin2A)
Unit Circle: 2[(√2/2)cos2A + (√2/2)sin2A][(√2/2)cos2A +(√2/2)·sin2A)]
Expand: 2[(1/2)cos²2A + cos2A·sin2A + (1/2)sin²2A]
Distribute: cos²2A + 2cos2A·sin2A + sin²2A
Pythagorean Identity: 1 + 2cos2A·sin2A
Double Angle: 1 + sin4A
LHS = RHS: 1 + sin4A = 1 + sin4A 
Answer:
y=12/5 (in decimal notation y=2.4)
Step-by-step explanation:
the value of 7y-2 = 10 more than 2y
7y-2 = 10+2y
7y-2y = 10+2
5y = 12
y = 12/5
y = 2.4
Answer:
cost = 1.35n
$33.75 for 25 songs
Step-by-step explanation:
Based on the numbers given, the cost is proportional to the number of songs downloaded. The constant of proportionality is the cost of one song: 1.35.
cost = 1.35n
For 25 songs, ...
cost = 1.35·25 = 33.75 . . . . dollars
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The equation is ...
cost = 1.35n
