The coefficient of 3+7d is 7
7 is the coefficient of the variable d
7d + 2 < 51 7d < 49 d < 7
d is the variable here.
The variable is "d".
7d + 2 7 is the only coefficient
The coefficient of 3+7d is 7
7 is the coefficient of the variable d
The coefficient would be the number multiplied by the variable, in this case: 7
7d + 2 < 51 7d < 49 d < 7
2
The variable is d, in the algebraic expression 7d+2
2
5de+9e+7d+10e=5de+7d+19e
d is the variable here.
The commutative property.
The variable is "d".