Will give brainliest to whoever answers first

What is the y intercept of f(x)=(1/2)^x?

45 was divided by a power of ten to get 4.5. what power of ten was it divided by? people 4.5

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