-7
15-X
(56/8) -8
NO
8 + x 40 is not a valid mathematical expression.
8+(7x9)
It is: 7*(8*15) = 840
The expression for 7 less than 15 is written as (15 - 7). When you calculate this, it equals 8. Therefore, 7 less than 15 can be expressed as (15 - 7 = 8).
It is: 8+7 = 15
It is a more complicated mathematical expression.
Yes, a mathematical expression can have no variables, but such an expression is usually not very useful. An example of a valid expression without variables is: 1+1=2
It means "a Mathematical Expression".
Average speed can be represented by the mathematical expression "distance x time."