Answer:
Johnny is wrong.

Step-by-step explanation:
Johnny is wrong.
A better definition would be:
is the set of all elements that belong to at least one A or B.
So, the elements that belong to both A and B, like c and d in this exercise, also belong to
.
So:

Answer:
13 in
Step-by-step explanation:
let w be width then length is w + 6
the area (A) of a rectangle is calculated as
A = length × width , then
A = w(w + 6) = 91 , that is
w² + 6w = 91 ( subtract 91 from both sides )
w² + 6w - 91 = 0 ← in standard quadratic form
(w + 13)(w - 7) = 0 ← in factored form
equate each factor to zero and solve for w
w + 13 = 0 ⇒ w = - 13
w - 7 = 0 ⇒ w = 7
however, w > 0 then w = 7
and length = w + 6 = 7 + 6 = 13 in
Answer:
7
Step-by-step explanation:
f(x) means y, it is equal to the value of y, so f(x) = y
so, f(1) means to find the value of y when the value of x is 1, and that is 7, since 7 is the value of y indicated when the value of x is 1.
I hope this is helpful.
Answer:
<h2>
aₙ = 7n - 10</h2>
Step-by-step explanation:
The nth term: 
So:
a₄ = a₁ + 3d
18 = a₁ + 3d ⇒ 3d = 18 - a₁
a₇ = a₁ + 6d
39 = a₁ + 6d
39 = a₁ + 2(18 - a₁)
39 = a₁ + 36 - 2a₁
39 = 36 - a₁
a₁ = -3
3d = 18 - (-3)
3d = 21
d = 7
So the nth term:

The <em>trigonometric</em> expression
is equivalent to the <em>trigonometric</em> expression
.
<h3>How to prove a trigonometric equivalence</h3>
In this problem we must prove that <em>one</em> side of the equality is equal to the expression of the <em>other</em> side, requiring the use of <em>algebraic</em> and <em>trigonometric</em> properties. Now we proceed to present the corresponding procedure:












The <em>trigonometric</em> expression
is equivalent to the <em>trigonometric</em> expression
.
To learn more on trigonometric expressions: brainly.com/question/10083069
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