Answer:
53°
Step-by-step explanation:
17² = 18² + 20² - 2(18)(20) cos Q
289 = 324 + 400 - 720 cos Q
289 = 724 - 720 cos Q
-435 = -720 cos Q
0.6042 = cos Q
Q = 52.83
Answer:
y=2x-11
Step-by-step explanation:
X=number of corect
y=number of incorrect
5 points for each correct so 5x
-1 point for each incorrect so -y
5x-y=76
solve for x and y
I like putting it into slope intercep tofrm which is y=mx+b
add y to both sides
5x=76+y
subtract 76 from both sides
5x-75=y
y=5x-76
subsitute values for x and get values for y
remember, that julia cannot answer a negative number of incorrect questions so y must be greater than or equal to 0
so solve for minimum
0<u><</u>5x-76
add 76 to both sides
76<u><</u>5x
divide by 5
15.2<u><</u>x
you cannot answer a fraction of a correct quesiton so round up
16 is the minumum number of queswtions correctlyh answered
so
x<u>></u>16
subsitute 16 for x
y=5(16)-76
y=80-76
y=4
as we subsitute more numbers over 16, we get these points
so (x,y)
(16,4)
(17,9)
(18,14)
(19,19)
(20,24)
(21,29)
(22,34)
(23,39)
x=correct answer
y=wrong answers
