Answer:
-10
Step-by-step explanation:
Let x = number
10 less than a number is the same number doubled
x-10 = 2x
Subtract x from each side
x-10-x = 2x-x
-10 = x
The number is -10
13
3 x 3 = 9
7 + 3 = 10
7 + ? = 3 + 7 + 3 + 7
7 + ? = 20
? = 13
Brainiliest pleaseeeeee
if the answer is the value of x then it would be 13.5
