for simultaneous equations in variables x and y d x² = 49 Dy= -63, D= 7 then what is the value of x?

Which expression calculates the speed in meters per second of an object that travels a distance of 100 m every 20 seconds

How can we find the measure of an exterior angle if we know the measurement of an interior angle

Noor brought 21 sheets of stickers. she gave 1/3 of a sheet to each of the 45 students at recess. she wants to give teachers 1 1/2 sheets each.