Question

If A= 2x -7y+5z-7, B=y +7 z +5 and C= 3y +2 z -5 x, find A + B – C.

Please help

Answer 1

Step-by-step explanation:

A=2x-7y+5z-7

B=y+7z+5

C=3y+2z-5x

Then we should find A+B-C

First find A+ B

i.e.,

(2x-7y+5z-7)+(y+7z+5)

2x-7y+y+5z+7z-7+5

2x-6y+12z-2

Here we got A+B=2x-6y+12z-2

Now finding A+B -C

(2x-6y+12z-2)-(3y+2z-5x)

If '-' is before "( )" then signs will change for the terms that are present in that "( )".

2x-6y+12z-2-3y-2z+5x

2x+5x-6y-3y+12z-2z-2

7x-9y+10z-2

Then A+B-C=7x-9y+10z-2

Hope it will help