What is the value of b? 0.4(3b 10)=19

What is the effect on the graph of the parent function f(x) = x when f(x) is replaced with 3f(x)? a) shifts the line 3 units up b) shifts the line 3 units down c) increases the slope of the line by a factor of 3 d) decreases the slope of the line by a factor of 3

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

Linda loans her friend $250 with a 5% monthly intrest rate. how much was the whole loan?