Question

Solve for x and y in the following sequences:

A) Arithmetic: 1.4, x, y, 9.5
B) Geometric: 5, x, y, 135

Answer 1

a) x=4.1,y=6.8 b) x= ,y=

Explanation:

a)Tn= a+(n-1)d

a=1.4

d=unknown

to find d use the terms given to solve

using the fourth term

9.5=1.4 + (4 -1)d

9.5= 1.4+(3)d

9 5-1.4=3d

8.1=3d

8.1/3=3d/3

2.7 =d

To find x

Tn=a+(n-1)d

x=1.4+(2-1)2.7

x= 1.4+(1×2.7)

x=1.4+2.7

x=4.1

To find y add 2.7 to x

y=4.1+2.7

y=6.8