Answer:
1. 12x
2. 12x-7
Step-by-step explanation:
1. distribute the 2 to both terms to get 10x+2x then add those together to get 12x OR add 5x to x to get 6x then distribute the (multiply by) 2 to get 12x
2. combine 3x and 9x to get 12x then write -7 to get 12x-7
