Question

(2) The weight of Manesh is 3 kg less than twice the weight of Bhavesh. In
their total weight is 78 kg, find the weight of both.​

Answer 1

Let weight of Bhavesh be= x kg

then weight of Manesh= (2x-3) kg

Given their sum of weights= 78 kg

therefore,

x+2x-3= 78

3x-3= 78

3x= 78+3

3x= 81

x=81/3

x=27 kg

hence weight of Bhavesh= 27 kg

and weight of manesh = (2x-3)

                                      = 2(27)-3

                                      = 54-3

                                       =51 kg

So you got your answer, hope it helps.

P.S.

It should be mass not weight because weight is when gravity acts on a body.

Answer 2

Step-by-step explanation:

Let Wm = weight of Manesh

Wb = weight of Bhavesh

Solution

Wm = 2Wb - 3kg Eq. 1

Wm + Wb = 78 kg Eq. 2

In Eq. 2 transpose Wm to the right side

Wb = 78 kg - Wm Eq. 3

Plug in Eq.3 to Eq.1

Wm = 2Wb - 3kg

Wm = 2(78 kg - Wm) - 3 kg

Wm = 156 kg - 2Wm - 3 kg

Combine like terms

Wm + 2Wm = 156 kg - 3 kg

3Wm = 153 kg

Divide both sides by 3

(3Wm)/3 = 153 kg/3

Wm = 51 kg Eq.4

Plug in Eq.4 to Eq.3

Wb = 78 kg - Wm

Wb = 78 kg - 51 kg

Wb = 27 kg

Therefore, the weight of Manesh is 51 kg while the weight of Bhavesh is 27 kg