Suppose that f : x → y is a function and that a is a σ-algebra of subsets of x. show that the following collection of subsets of y is also a σ-algebra: b : = {b ⊂ y : f −1 (b) ∈ a}

Write a real-world solution that can be represented by the equation y = 7x be sure to explain what the variables represented in the solution

The gades foundation and hbm corporation are eager to donate generously to their favorite charities. the gades foundation donated $250 in the first month, and each month afterward their cumulative donation total increases by 100$ the hbm corporation donated $64, in the first month, and each month afterward their cumulative donation total increases by 75%. in which month will the hbm corporation's cumulative donation total first exceed the gades foundations' cumulative donation total?

What statement is true? 2x^2-9x+2=-1