Answer:
C) 
Step-by-step explanation:
By the cos double angle formula, we know 
Substituting 
into the formula, we get
.
The answer is C.
A function assigns the value of each element of one set to the other specific element of another set. The total amount of credit cards opened at the two locations is given as 45+3t.
<h3>What is a Function?</h3>
A function assigns the value of each element of one set to the other specific element of another set.
Given that the number of credit cards, A, that is opened t months since January can be modeled by the function A(t) = 20 + 4t, while the number of credit cards opened at another location, B, is defined by the function B(t)=25−t.
Now, the total number of credit cards that are opened at both the location together will be,
Total number of credit cards = A(t) + B(t)
= 20 + 4t + 25 - t
= 20 + 25 + 4t - t
= 45 + 3t
Hence, the total amount of credit cards opened at the two locations is given as 45+3t.
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Step 1 : Simplify both sides
-5(6a+21)=-15
(-5)(6a)+(-5)(21)=-15
-30a-105=-15
Step 2 : Add 105 to both sides
-30a-105+105=-15+105
-30a=90
Step 3 : Divide both sides by -30
-30a=90
—————
-30 -30
a = -3
Answer:
x=5.6
y=-5.6
Step-by-step explanation:
3x - 5y = 14 Equation 1
– 2x + 2y = 0 Equation 2
Simultaneous equation can be solved either through elimination method or substitution method. But we use elimination method for this question
Multiply equation 1 by -2 (the coefficient of x in equation 2) and multiply equation 2 with 3 (the coefficient of x in equation 1), so that x will have the same coefficient in the new equations, and easy to eliminate
-2(3x - 5y = 14)
-6x+10y=-28 Equation 3
3(– 2x + 2y = 0)
-6x+6y=0 Equation 4
Subtract equation 4 from 3 to eliminate x
-6x+10y=-28
-6x+6y=0
-6x-(-6x)=-6x+6x=0
10y-6y=5y
-28-0=-28
5y=-28
y=-28/5
y=-5.6
Substitute for y in equation 2
– 2x + 2y = 0
– 2x + 2(-5.6) = 0
-2x-11.2=0
-2x=11.2
x=-11.2/2
x=5.6
Answer:
D. 
Step-by-step explanation:
Area of rectangle = 
Length of rectangle = (x - 8)
Width = (x + 11)
Area of rectangle = 
Expand the expression
(distributive property of multiplication)
Combine like terms
Expression for the area of the rectangle =
