Simplify this expression: 21-4x + 6)

Match each equation with the operation you can use to solve for the variable. subtract 10. divide by 10. divide by 5. subtract 18. multiply by 10. add 18. add 10. multiply by 5. 5 = 10p arrowright p + 10 = 18 arrowright p + 18 = 5 arrowright 5p = 10 arrowright

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?

Whats are the trickiest steps to do when adding or subtracting rational expressions? how does knowledge of rational numbers u in adding and subtracting rational expressions?