Joshua runs each day after school to train for his cross country team. He ran three miles the first week, six the second week, and nine the third week. If this pattern continues, how many miles will he be running during the fifteenth week of school?

He will be running 45 miles in the during the fifteenth week of school.

Step-by-step explanation:

Given: Joshua runs each day after school to train for his cross country team.

He ran 3 miles in first week, 6 miles in second week, 9 miles in third weeki.e. sequence will be  3, 6, 9 ,(multiple of 3.)

The number of miles he will be running during the fifteenth week of school = 15 x 3

=45

Hence, he will be running 45 miles in the during the fifteenth week of school.

7x-81= -2+72
7x= -2+72+81
7x= 151
x=21 4/7

For explanation: whenever a number passes a equal sign, it becomes its opposite. For example once the number 2 passes through the equal sign it become -2

Hope you get it! Hope this helps :)