SOLUTION: I need help to solve a problem and i didn't know at what section to put it so i put it here . In an arithmetic progression , a4=7 and a9=22 Find a14 Plase help me .

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: I need help to solve a problem and i didn't know at what section to put it so i put it here . In an arithmetic progression , a4=7 and a9=22 Find a14 Plase help me .      Log On


   



Question 1011903: I need help to solve a problem and i didn't know at what section to put it so i put it here .
In an arithmetic progression , a4=7 and a9=22
Find a14
Plase help me .

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
In an arithmetic progression , a4=7 and a9=22
a(1) + 3d = 7
a(1) + 8d = 22
-----
Subtract and solve for "d"::
5d = 15
d = 3
-----
Solve for "a(1)"::
a(1) + 3*3 = 7
a(1) = -2
====================
Find a14 = a(1) = 13*d
a(14) = -2 + 13*3
a(14) = 37
-----------------
Cheers,
Stan H.
----------