Answer
1. [tex]2a+3b-a=a+3b[/tex]
2. [tex](4x+3y)-(2x-5y)=2x+8y[/tex]
3. [tex]-3(2x-1)-5=-6x-2[/tex]
4. [tex]7xy-2xz+4xz-12xyz+2zx=7xy+4xz-12xyz[/tex]
5. [tex]-3(2x-5)-4(x+7)=-10x-13[/tex]
Step-by-step-explanation
1. The given expression is [tex]2a+3b-a[/tex]
Regroup the terms to obtain;
[tex]=2a-a+3b[/tex]
Simplify to get;
[tex]=a+3b[/tex]
2. The given expression is [tex](4x+3y)-(2x-5y)[/tex]
Expand the brackets to get;
[tex]=4x+3y-2x+5y[/tex]
Regroup the terms to get;
[tex]=4x-2x+3y+5y[/tex]
Simplify
[tex]=2x+8y[/tex]
3. The given expression is [tex]-3(2x-1)-5[/tex]
Expand the brackets to get;
[tex]=-6x+3-5[/tex]
Simplify;
[tex]=-6x-2[/tex]
4. The given expression is [tex]7xy-2xz+4xz-12xyz+2zx[/tex]
Regroup the terms to get;
[tex]=7xy-2xz+2zx+4xz-12xyz[/tex]
Apply the commutative property of multiplication to get;
[tex]=7xy-2xz+2xz+4xz-12xyz[/tex]
Simplify;
[tex]=7xy+4xz-12xyz[/tex]
5. The given expression is [tex]-3(2x-5)-4(x+7)[/tex]
Expand the brackets to get;
[tex]=-6x+15-4x-28[/tex]
Regroup the terms to get;
[tex]=-6x-4x-28+15[/tex]
Simplify;
[tex]=-10x-13[/tex]
