Question

In an ap the sum of four terms is 20and the sum of their squares is 120 find the four terms​

Answer 1

Step-by-step explanation:

a+a+d+a+2d+a+3d = 20

4a + 6d = 20

2a + 3d = 10 -----(1)

a² + (a+d)² + (a+2d)² + (a+3d)² = 120

a²+a²+2ad+d²+a²+4ad+4d²+a²+6ad+9d² = 120

4a²+12ad+14d² = 120

(2a+3d)² + 5d² = 120

5d² = 120-100 = 20

d² = 4 , d = 2

2a + 6 = 10 , 2a = 4 , a = 2

The terms are 2 , 4 , 6 & 8