Haley is reading a book. Yesterday, she read 19 pages. The day before, she read 20 pages. How many pages much she read today in order to average 20 pages per day

21

Step-by-step explanation:

she will need to read 21 pages today

Step-by-step explanation:

The average is the middle number if u  want 20 u need 1 number more and one less

i can you with this question sweetie!

step-by-step explanation:

hope it you

step-by-step explanation:

sin(7pi/6 - pi/3)  

= sin(7pi/6 - 2pi/6)  

= sin(5pi/6)  

= sin(pi - pi/6)  

= sin(pi/6)  

= 1/2  

sin 7pi/6 - sin pi/3  

= sin (pi + pi/6) - sin pi/3  

= -sin pi/6 - sin pi/3  

= -1/2 - sqrt(3)/2  

= -(1+sqrt(3))2