The 15th term of arthimetic sequence is 43 and the common difference is 4 find the first term

Step-by-step explanation:

hello :

the nth term of an arithmetic sequence is :

An =An+(n-p)d   a common difference is : d  

let : n=15    and   p=1    d= 4     A15 =43

A15 = A1 + (15-1)(4)

43= A1 +56

A1= 43-56 = - 13

b. 18

step-by-step explanation:

so the equation for this is:

ab^2=ac⋅ad

ab being the top length of 6 and ac being the length of 2 and ad being the length of x. let's plug into the equation:

6^2 = 2x

now lets just solve for x:

36 = 2x

18 = x

i hope that !

ask i dont know either ; (

step-by-step explanation: