4. Which term of the AP:3, 8, 13, 18,...,is 78?

Step-by-step explanation:

The first term of the AP (a) = 3

and common difference (d) = 8-3= 5

therefore, a+(n-1)d = 78

=> 3+(n-1)5= 78

=> n-1=75/5

=> n-1 = 15

=> n= 16

16th term of the AP is 78

the equation for this situation is y=122+45. to solve the equation you would add 45 and 122 to get a total of 167lbs. in conclusion, grace's weight eight weeks ago was 167lbs.