Answer:Robert's minimum age is 11 years.
Step-by-step explanation:
Let x represent George's age.
Let y represent Edward's age.
Let z represent Robert's age.
George is twice as old as Edward. It means that
x = 2y
Edward's age exceeds Robert's age by 4 years. It means that
z = y - 4
If the sum of the three ages is at least 56 years, it means that
x + y + z ≥ 56 - - - - - - - - - - 1
Substituting x = 2y and z = y - 4 into equation 1, it becomes
2y + y + y - 4 ≥ 56
4y - 4 ≥ 56
4y ≥ 56 + 4
y ≥ 60/4
y ≥ 15
z = y - 4 = 15 - 4
z ≥ 11
X is the number of hours studied, so replace x with 3 in the equation:
y = 6.8(3) + 60
y = 20.4 + 60
y = 80.4
Round down to 80.
The answer would be A.
<h3>
Answer: cos(76)</h3>
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Explanation:
The original expression is of the pattern cos cos + sin sin. This pattern matches the second identity in the hint. Specifically, we'll say the following:
cos(A - B) = cos(A)cos(B) + sin(A)sin(B)
cos(A)cos(B) + sin(A)sin(B) = cos(A - B)
cos(94)cos(18) + sin(94)sin(18) = cos(94 - 18)
cos(94)cos(18) + sin(94)sin(18) = cos(76)
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We can verify this by use of a calculator. Make sure your calculator is in degree mode.
- cos(94)cos(18) + sin(94)sin(18) = 0.24192
- cos(76) = 0.24192
Both expressions give the same decimal approximation, so this helps confirm the two expressions are equal. You could also use the idea that if x = y, then x-y = 0. Through this method, you'll subtract the left and right hand sides and you should get (very close to) zero.
A reflection is a transformation across a line called the line of reflection, so that the line of reflection is the perpendicular bisector of each segment joining each point and its image. ... A translation is an isometry , so the image of a translated figure is congruent to the preimage.
