Question

What should be subtracted from $3xz-4y+5xy+20$ to obtain $-x-y+6xy+5xz+20$?

• A. $-2xz-xy-3y+x$
• B. $2xz+xy-3y+x$
• C. $2xz+xy+3y-x$
• D. $-2xz-xy-y+x$

Answer 1

The correct option is A $-2xz-xy-3y+x$

Let the expression to be subtracted from $3xz-4y+5xy+20$ be A.
$\Rightarrow (3xz-4y+5xy+20)-A=(-x-y+6xy+5xz+20)$
$\Rightarrow A=(3xz-4y+5xy+20)-(-x-y+6xy+5xz+20)$
Grouping all the like terms together, we get
$A=(3xz-5xz)+(5xy-6xy)+(-4y+y)+\left(x\right)+(20-20).$
$\Rightarrow A=-2xz-xy-3y+x$
Hence, the expression that is to be subtracted from $3xz-4y+5xy+20$ is $-2xz-xy-3y+x.$