Respuesta :
Answer:
s=650
Step-by-step explanation:
s=n/2(2a+(n-1)d)
s=20/2[2x4+(20-1)3]
s=20/2(2x4+19x3)
s=20/2(8+57)
s=20/2x65
s=10x65
s=650
Answer:
s=650
Step-by-step explanation:
Sum of 'n' terms formula is given by:-
s=n/2(2a+(n-1)d)
s=20/2[2x4+(20-1)3]
s=20/2(2x4+19x3)
s=20/2(8+57)
s=20/2x65
s=10x65
s=650