A(n)=4+4(n-1)
a(n)=4+4n-4
a(n)=4n
76=4n
n=19
The sum of any arithmetic sequence (series are infinite) is:
(a+a(n))(n/2)
The average of the first and last terms times the number of terms, in this case we found that n=19 so:
19(4+76)/2=760
Answer:
x° is 66°
Step-by-step explanation:
From the given diagram, we have;
∠JIH = 105° Given
∠IDJ = 39° Given
Therefore, we have;
∠JID and ∠JIH are supplementary angles, by the sum of angles on a straight line
∴ ∠JID + ∠JIH = 180° by definition of supplementary angles
∠JID + 105° = 180° by substitution property
∠JID = 180° - 105° = 75° by angle subtraction postulate
∠JID = 75°
∠IDJ + ∠JID + ∠IJD = 180° by the sum of interior angles of a triangle
∠IJD = 180° - (∠IDJ + ∠JID) = 180° - (39° + 75°) = 66° angle subtraction postulate
∠IJD = 66°
∠x° ≅ ∠IJD, by vertically opposite angles
∴ ∠x° = ∠IJD = 66° by the definition of congruency
∠x° = 66°
D fed ifjk vs cjsioxhdjducjskvuhdkfuxhxiufuc
Answer:
yes Cecilia make her first mistake in step 2
