There are about 6 billion people on earth. if they all lined up and held hands, how long of a line would they form in km? (assume each person is 1 meter apart.)

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

Combine like terms to make a simpler expression 3z+z

Write the equations in logarithmic form 9^4=6,561