Answer:
12
Step-by-step explanation:
since you already know that the short sides together are 4 inches, that means there's 18 inches left, so 9 inches for each long side. Add 3 to 9 and you have your unknown number.
Answer:
it's answer is 2a + 6a - 21
Step-by-step explanation:
2a + 3 ( 2a - 7)
= 2a + 6a - 21
Hope it will help :)❤
Take out the variable to add the numbers because it is the same variable throughout so 6-5+7=8 then add the n^2 o get 8n^2