The expression is 9*x.
There is no specific name. If the numerator and denominator are polynomials in the variable then the question describes an algebraic fraction. But there is no reason at all to assume that they are polynomials. There is no specific phrase that describes sin(x)/x, for example.
It is a "rational number".
if there are no comparison signs (equals or inequalities, ie =, >, < etc) then it is an expression, eg "x + 5" If there is a comparison sign which is not equals, then it is an inequality, eg "x > 5"
There is no 'last' integer, the expression 'infinity' is sometimes used to describe a quantity, but, it's not a last number.
Which phrase describes the variable expression 6.w
N + 5 With "N" being the variable.
n + 11
x + 138
Your variable (a number) X, minus 100. X - 100
This question cannot be answered. You will have to give me more detail.