Question

calcular a soma dos dez primeiros termos da pa de primeiro termo sendo 1,87 sendo a razao 0.004

Answer 1

a1 = 1.87 = 187/100 
n = 10
r = 4/1000 = 1/250 ***
a10 = a1 + 9r
a10 = 187/100 + 9 ( 1/250) = 187/100 + 9/250 = (935 + 18)/500 =953/500

S10 = ( 187/100 + 953/500)*5
S10 =[ ( 935 + 953)/500] * 5 = (1888/500) * 5/1  = 9440/500 =944/50 =18.88
PROVA
a1 = 187/100
a2 = 187/100 + 1/250 = ( 935 + 2)/500 = 937/500
a3 = 937/500 + 1/250 = ( 937 + 2)/500 = 939/500
a4 = >>>>>>>>>>>>>>>>>>>>>>>>>>= 941/500
a5 =>>>>>>>>>>>>>>>>>>>>>>>>>> = 943/500
a6 = >>>>>>>>>>>>>>>>>>>>>>.>>> = 945/500
a7= >>>>>>>>>>>>>>>>>>>>>>>>>> = 947/500
a8 = >>>>>>>>>>>>>>>>>>>>>>>>>  = 949/500
a9 = >>>>>>>>>>>>>>>>>>>>>>>>>  = 951/500
a10 = >>>>>>>>>>>>>>>>>>>>>>>>  = 953/500  confere