Question

A-4B+2C=16
2A+7B-5C=83
a+B-C=?

Answer 1

Answer:

hope it helps you.......

Answer 2

According to the question

A-4B+2C = 16 .......(i)

2A+7B-5C= 83 ..........(ii)

2× (i) shows that

2A — 4B+2C = 32

or, 2A= 32- 2C+4B....(iii)

from the equation (ii)

we can say that

2A= 83-7B +5C .....(iv)

according to the equation (iii) & (iv)

2A= 32+8B- 4C = 83- 7B + 5C

OR, 8B- 4C+ 7B- 5C = 83-32

OR, 15B - 9C = 51

OR,5B -3C = 17

OR,B = (17+3C)/5

From equation (i) , we can get

A= 16+4B -2C = 16+{4×(17+3C)}/5 -2C = (148+2C)/5

Hence

A+B-C = (148+2C)/5 +(17+3C)/5 -C = (148+2C+17+32-5C)/5 = 165/5 = 33