Question

what should be added to to a minus b + c to make it a + b - 2 C​

Answer 1

Answer:

Let the number to be added be x

(2a - b + c) + x = a + b - 2c

x = a + b - 2c - (2a - b + c)

x = a + b - 2c - 2a + b - c

x = -a + 2b - 3c

Answer 2

Answer:

create your equation

if we substrate -b + c from b-2c then we get the number to be added.

X is the number to be added.

-b + c + X = + b - 2c

c. + X = +B +b - 2c. taking -b to RHS

X. = 2b -3b

So the number added to - b +c is 2b -3c

Verification

-b + c + 2b - 3c = b - 2c

b + c - 3c = b - 2c

b -2c = b -2c

so verified.

Thanks.