The phrase "10 more than the quotient of a number and equal -21" can be expressed as the following algebraic expression:
Let [tex]\(x\)[/tex] be the number. The expression is:
[tex]\[ \frac{x}{-21} + 10 \][/tex]
This represents the quotient of the number [tex]\(x\)[/tex] divided by -21, with 10 added to the result.