Hi! I really need help, I will give brainliest to whoever is right! Simplify the following equations:
#1, (7+2a)⋅3-20
#2, 7⋅(a+5)-30
#3, (3-a)⋅2+a
#4, (7+2a)⋅3-20
#5, (a+3)-(a+2)
#6, (a+20)-(a-20)
#7, (2a+1)-(a+2)
Answer as much as you can!

News cameras take an overhead picture of a crowd at an outdoor event journalist then count the total number of people in the picture and use the sample of estimate the total number of people in the crowd this process is an example of

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