In Exercises 15-17, solve the equation. 15. 312 - t = 0
16. 5y + 10y = 0
17. 21n + 12n² = 0

The area of square garden is 300m squared. how long is the diagonal?

:24% of students in a class are girls. if there are less than 30 students in this class, how many students are there? how many girls are there?

In need of in the diagram, ∠abc is a right angle. ∠dbc = 30°27'40". find the measure of ∠abd.