Answer:
Step-by-step explanation:
These binomials make up the difference of squares.
3x * 3x = 9x^2
3x * 5 = 15x
-5 * 3x = - 15x
-5 * 5 = - 25
Notice the 2nd and 3rd terms. They are equal except that one is plus and the other minus. That means they cancel. You are left with
9x^2 - 25
Answer:
see explanation
Step-by-step explanation:
(5)
Using the trigonometric identity
sin²x + cos²x = 1 ⇒ cos²x = 1 - sin²x
Given
3sin²Θ + 2cos²Θ - 2
= 3sin²Θ + 2(1 - sin²Θ) - 2
= 3sin²Θ + 2 - 2sin²Θ - 2
= sin²Θ
(6)
Using the trigonometric identity
secx = 
Consider the left side

= 
=
= secx = right side ⇒ verified
(7)
Using the trigonometric identity
1 + cot²x = csc²x
Given
sin²x. cot²x + sin²x ← factor out sin²x from each term
= sin²x(cot²x + 1)
= sin²x. csc²x
= sin²x ×
= 1
Once cross multiplied you end up with this:
15x+75=20x−30
Next subtract 20x from both sides.
15x+75−20x=20x−30−20x
−5x+75=−30 -----------> Answer
Now subtract 75 from both sides
−5x+75−75=−30−75
−5x=−105
Now divide by -5 on both sides.
-5/-5x = -105/-5
<h3 /><h3>
x = 21 --------------> ANSWER</h3>
20% of 2100 is 420
So the tax is $420
Then 2100-420= 1680
So he has $1680 left after paying the tax.