The sum of -21.8 and a number is positive. Identify a possible value for that number. Explain you selection.

John used linear combination to solve the system of equations shown. he did so by multiplying the first equation by -3 and the second equation by another number to eliminate the x-terms. what number did jonas multiply the second equation by? 4x-6y=23x+5y=11

The radius of the earth is two times the radius of the moon. what fraction of the volume of the earth is the volume of the moon?

Find the volume of the solid obtained by rotating the region enclosed by the curves y=1x and y=7^-x about the x-axis. (use symbolic notation and fractions where needed.) volume =