Question

Given a 3= 15 , s 10 = 125 , find d and a 10

Answer 1

Answer:

d=-1 and a10=8

Step-by-step explanation:

a3=15, s10=125

we can write a+2d=15---->(1)

10/2[2a+9d]=125

= 5[2a+9d]=125

=>2a+9d=25---->(2)

(1)*(2)=>2a+4d=30----->(3)

(2)-(3)=> 5d=-5

d=-1

eq (1):- a+2d=15

a+-1*2=15

a=15+2=17

to find a10

a10=a+9d

=17+9*(-1)

=17-9=8

.•. a10=8 and d=-1