Hi there!

We are given:
cos(7x)cos(4x) = -1 - sin(7x)sin(4x)
Begin by moving all terms with variables to one side:
cos(7x)cos(4x) + sin(7x)sin(4x) = -1
The corresponding trig identity is cos(A - B). Thus:
cos(7x - 4x) = cos(7x)cos(4x) + sin(7x)sin(4x) = -1
cos(3x) = -1
cos = -1 at π, so:
3x = π
x = π/3
We can also find another solution. Let 3π = -1:
3x = 3π
x = π
Thus, solutions on [0, 2π) are π/3 and π.
Answer: x y
-2 15
-1 9
0 7
1 9
2 15
3 25
Step-by-step explanation:you always do the exponent first, then you multiply that by that two, and then you add 7.
Answer:
11/4 or 2.75 pints
Step-by-step explanation:
We want to find the difference between the original amount of blueberries and the amount she ate
original amount-amount ate
3 1/2 -3/4
To subtract, we need common denominators
The common denominator of 2 and 4 is 4
3 1/2=7/2
Multiply by 2/2 to get a common denominator of 4
7/2*2/2=14/4
Now, we have common denominators and can subtract
14/4-3/4
Subtract the numerators, and leave the denominators as 4
11/4 =2.75
She has 11/4 or 2.75 pints left
Answer: The result is one half (
)
Step-by-step explanation:
We have the following expression:

Since both fractions have the same denominator, we can just add both numerators and keep the denominator:

Dividing numerator and denominator by
:
This is the result
Option 2.
1. Simplify 7 + (12 - 9) + 7 × 3(8 - 5)
According to the Order of Operations, contents of parentheses are evaluated first. This gives
... 7 + 3 + 7 × 3 × 3
Then multiplication and division are performed left to right.
... = 7 + 3 + 21 × 3
... = 7 + 3 + 63
Followed by addition and subtraction left to right.
... = 10 + 63
... = 73
A Google search box can be relied upon to do the operations in the correct order.
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2. When the expression is rewritten, a different result is obtained. This is because the operations indicated by the second set of parentheses are altered.
... (7 + 12) - 9 + (7 × 3)8 - 5
... = 19 - 9 + 21 × 8 - 5
... = 19 - 9 + 168 - 5
... = 10 + 168 - 5
... = 178 - 5
... = 173
In the first expression, both +8 and -5 are multiplied by 21. In the rewritten expression, only +8 is multiplied by 21.