Answer:
1. 10x + 14
2. 2x + 11y - 7
3. -10x - 11
Step-by-step explanation:
1.
[tex]4x+5+7x-3+x+12=\\10x+14[/tex]
2.
[tex](7x+9y-1)-(5x-2y+6)=\\7x+9y-1-5x+2y-6=\\2x+11y-7[/tex]
3.
[tex]-2(2x+5)-6x-1=\\-4x-10-6x-1=\\-10x-11[/tex]
