Question

Find the sum of first 15 terms of the AP if its first term is 4 and common difference is -3​

Answer 1

Answer:

-255 is answer

Step-by-step explanation:

S15= 15/2*(2(4)+14(-3))

S15= 15/2*(8+(-42))

S15= 15/2*(-34)

S15= 15*(-17)

S15= -255