Answer:

Step-by-step explanation:
Combine like terms (terms with the same exponent).

"Standard form" means to list terms so the exponents go from high to low (descending order).
Answer:
First one is 6 16/21
Second one is 3 14/15
Step-by-step explanation:
" The opposite of " could be the answer
Answer: x=4
10x-3x=30-2
7x=28
X=4