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

Solution:

It is given that

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

We know that

x + y = -4/9 + 5/12

LCM of 9 and 12 is 36

= (-4 × 4 + 5 × 3)/ 36

By further calculation

= (-16 + 15)/36

= -1/36

Reciprocal of x + y = 1/(-1/36) = -36

Therefore, the reciprocal of x + y is -36.

✦ Try This: Find a rational number exactly halfway between: 1/19 and 1/17

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

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

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

Summary:

Taking x = -4/9, y = 5/12 and z = 7/18, the reciprocal of x + y is -36.

☛ Related Questions:

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