Is Dana school closes a phone tree is used contact each students family the secretary calls three families then each family calls 3 other families and so on, how many families will be notified by the sixth round of calls?

1*3^6 or 2187

Step-by-step explanation:

1*3=3

3*3=9

9*3=27

27*3=81

81*3=243

243*3=729

729*3=2187

5x+40

5(x + 8)

7x - 49

7(x - 7)

18x + 9

9(2x + 1)

15x - 10

5(3x - 2)

step-by-step explanation:

for number one all you have to do is factor 5 out of 5x + 40

for number 2 factor 7 out of 7x - 49

for number three factor 9 out of 18x + 9

for number four factor 5 out of 15x - 10

step-by-step explanation:

step 1: solve one of the equations for one of the variables. let's solve the first equation for y:

step 2: substitute that equation into the other equation, and solve for x.

step 3: substitute x = 4 x = 4 x=4 into one of the original equations, and solve for y.