Taking x = -4/9, y = 5/12 and z = 7/18, find: the sum of reciprocals of x and y.

Solution:

It is given that

x = -4/9, y = 5/12 and z = 7/18

We know that

Reciprocals of x and y = 1/x and 1/y

Sum of reciprocals = 1/x + 1/y

Substituting the values

= 1/(-4/9) + 1/(5/12)

By further calculation

= -9/4 + 12/5

LCM of 4 and 5 is 20

= (-45 + 48)/20

= 3/20

Therefore, the sum of reciprocals of x and y is 3/20.

✦ Try This: Find a rational number exactly halfway between: 1/15 and 1/13

☛ Also Check: NCERT Solutions for Class 7 Maths Chapter 9

NCERT Exemplar Class 7 Maths Chapter 8 Problem 94(f)

Taking x = -4/9, y = 5/12 and z = 7/18, find: the sum of reciprocals of x and y.

Summary:

Taking x = -4/9, y = 5/12 and z = 7/18, the sum of reciprocals of x and y is 3/20

☛ Related Questions:

• Taking x = -4/9, y = 5/12 and z = 7/18, find: (x ÷ y) × z
• Taking x = -4/9, y = 5/12 and z = 7/18, find: (x - y) + z
• Taking x = -4/9, y = 5/12 and z = 7/18, find: x + (y + z)