What would be the fifth term inm this math sentence:  A (n) = - 3 - ( n - 1 ) ( 1.5 ) ?
153400
i believe it would be '-9'\nn=5 \n-3-(5-1)(1.5)\n-3-(4*1.5)\n-3-6\n-9
487838
1) Assuming an aritmetic sequence\n\nbn = b1 + (n-1)d \nletting b3=a1 = 20, then b7=a5 = 32, and b25 = b23\na5 = a1 + (5-1)d\n32 = 20 + (5-1)d\n32 = 20 + 4d\n12 = 4d\n3 = d\n\nb25 = a23 = 20 + (23-1)*3\nb25 = 20 + 22*3\nb25 = 20 + 66\nb25 = 86\n=====================================================\n2)\na75 = a1 + (75-1)d; d=-3\n\na75 = 5 + (75-1)*-3\na75 = 5 + 74*-3\na75 = 5 + -222\na75 = -217\n\nSn = n/2(a1+an)\nS75 = 75/2(5 + -217)\nS75 = 75/2(-212)\nS75 = -7950\n===================================================\n3) ????\n\na5 = 5*5 - 4 = 21\na15 = 5*15 - 4 = 71\na25 = 5*25 - 4 = 121\n\nOR MAYBE\n\na1 = 5*1 - 4\na1 = 5 - 4\na1 = 1\na30 = 5*30 - 4\na30 = 150 - 4\na30 = 146\n\nSn = n/2(a1+an)\nS30 = 30/2(1 + 146)\nS30 = 30/2(147)\nS30 = 2205\n================================================\n4)\n\nrth term is nCr-1m^n-(r-1)k^r-1\n\n5th term =\n4C4m^4-(5-1)k^5-1\n4C4 = 1\n\n5th term = k^4
253051
1st 5 terms: 3.14......\n1st 10 terms: 3.14.....
108578
the first term is A11=8/3^9\nAn = A1*q^(n-1)\nin our sequence A1=24 and q=3\ntherefore An=24*(1/3)^(n-1)\nlet's say 0.001 = 24*(1/3)^(n-1)\n0.001/24 = (1/3)^(n-1)\n1/24000 = ((1/3)^n)/(1/3)        /:1/3\n1/72000 = (1/3)^n\nn = (log(1/72000))/(log(1/3))\nn =  10.18\nwe want An to be less then 0.001 so we take a greater integer n, so n = 11 and A11 = 24*(1/3)^10 = 8/3^9
498351
U1=4-2*1=4-2=2\nU2=4-2*2=4-4=0\nU3=4-2*3=4-6=-2\nU4=4-2*4=4-8=-4\nU5=4-2*5=4-10=-6\n\nSo, the first five terms are 2,0,-2,-4,-6.\n\nb)There are a few ways of writing this one, but you can simply see that every number is in the form 4n+3 where n goes from 1 to infinity\nso you have 7,11,15,19,23,27,...\nso nth term would be an=4n+3 or an=an-1 + 4\n\nor you can write nth term as 7+4n where n goes from zero (from zero because you must have 7 included) to infinity.
764334
d=4\na=-1\ntn=a+(n-1)d\n=-1+(n-1)4\n=-1+4n-4\n=4n-5
905619
x=-3.5 if you want it in fraction it's 3and1/2 =P
889429
1) Yup. a_1 - 5 = a_2, so a_1 must be 3.\n2) What does the common ratio actually mean? Its any term divided by the term before it. So in this case, the common ratio is just (-3)/(-2) = 1.5. Now, how would you get the first term? To go from the first term to the second you'd multiply by 1.5; thus to go from the second to the first, divide by 1.5: -2/1.5 = -4/3 is the first term.
284235
This is a geometric sequence with a common ratio of (-1/4).\n\nLet:\n\nr = common ratio\na1 = 1st term = 80\na2 = 2nd term = -20\na3 = 3rd term = 5\na4 = 4th term = -5/4\na5 = 5th term \na6 = 6th term\na7 = 7th term\n.\n.\n.\na10 = 10th term\n\nSolution:\n\nr = a2/a1 = a3/a2 = a4/a3 = -20/80 = -1/4\n\na1 = 80 Given\na2 = (a1)(r)= 80r = -20 Given\na3 = (a1)(r)(r) = 80r^2 = 5 Given\na4 = (a1)(r)(r)(r) = 80r^3 = -5/4 Given\na5 = (a1)(r)^(5-1) = 80r^4 = 80(-1/4)^4 = 5/16 ANSWER\na6 = (a1)(r)^(6-1) = 80r^5 = 80(-1/4)^5 = -5/64 ANSWER\na7 = (a1)(r)^(7-1) = 80r^6 = 80(-1/4)^6 = 5/256 ANSWER\n.\n.\na10 = (a1)(r)^(10-1) = 80r^9 = 80(-1/4)^9 = -5/16384 ANSWER
981803
5 x (3 + 3) x 6  = 180\n\nEither the negative in front of your 5 is wrong, or you should've had a negative in front of 180.  In other words:\n\n-5 x (3 + 3) x 6  = -180\n\nHope that helped!\n\n~ ♥ ~
96233
+5,+12, -5, -12, +3.3
874116
-7,-10,-13 by putting n= 1 2 and 3
786690
u can do it by\n(n/2)(a+l)\nwhere \nn is no. of terms\na is first term\nl is last term
712412
the first one is\ny= -3/2+3
952696
n + (n - 5) + (n + 6) \n3n + 1
85542
A(5) = 1/2 + (5-1)(1/4)\nA(5) = 1/2 + (4)(1/4)\nA(5) = 1/2 + 1\nA(5) = 1 1/2
788016
5+4=9\n-5+4=-1\n4+(-3)=1\n4-(-3)=4+3=7\nhope that helps!!