Question

Calculate

1. 5+8+11+14+...+101
2. 50+19 1/2+ 48 1/3 + ... x (-20)

Answer 1

Answer:

1)

Step-by-step explanation:

1)tn=101 a=t1=5 d=3

tn=a+(n-1)d

101=5+(n-1)3

101=5+3n-3

101=2+3n

101-3=3n

99=3n

n=99/3

n=33

Sn=n/2[t1+tn]

Sn=33/2[5+101]

Sn=33/2*106

Sn=33*53

Sn=1749