Answer:
30
Step-by-step explanation:
A player answers x correct questions and y incorrect questions for a total of 40 questions.
x + y = 40
The score is obtained by subtracting y incorrect answers from two times the x of correct answers. The player's score is 50.
2x - y = 50
Use substitution to solve. Rearrange the first equation so that it is equal to y. Then, substitute the y-value into the second equation.
x + y = 40
y = 40 - x
2x - y = 50
2x - (40 - x) = 50
2x - 40 + x = 50
3x - 40 = 50
3x = 90
x = 30
Since x was made to represent correct answers, the player had 30 correct answers.
Therefore, slope of line DC = slope of line AC = -0.4.
The answer is D that is (18+41)+12 = 18+(41+12)
because A,B,C can be only be associative when
(A+B)+C= A+(B+C)
So by comparing the associative law with the options above , you will be able to get your answer
Answer:
Tn = 64-4n
Step-by-step explanation:
The nth term of an AP is expressed as:
Tn = a+(n-1)d
a is the common difference
n is the number of terms
d is the common difference
Given the 6th term a6 = 40
T6 = a+(6-1)d
T6 = a+5d
40 = a+5d ... (1)
Given the 20th term a20 = -16
T20 = a+(20-1)d
T20 = a+19d
-16 = a+19d... (2)
Solving both equation simultaneously
40 = a+5d
-16 = a+19d
Subtracting both equation
40-(-16) = 5d-19d
56 = -14d
d = 56/-14
d = -4
Substituting d = -4 into equation
a+5d = 40
a+5(-4) = 40
a-20 = 40
a = 20+40
a = 60
Given a = 60, d = -4, to get the nth term of the sequence:
Tn = a+(n-1)d
Tn = 60+(n-1)(-4)
Tn = 60+(-4n+4)
Tn = 60-4n+4
Tn = 64-4n
The number pattern would be 8x5 because each starfish has five arms. The answer is 40