What is the solution -4x = -20

What is the definition of exponential decay?

Me. i can't figure out this question. give an explanation too. .

Choose the equation below that represents the line that passes through the point (2, 4) and has a slope of 3. a) y − 4 = 3(x − 2) b) y − 2 = 3(x − 4) c) y + 4 = 3(x + 2) d) y + 2 = 3(x + 4)