Need help with some khan academy stuff

2.2 % per minute

35 minutes

Step-by-step explanation:

(0,23%) and (30, 89%)

We can find the slope

m = ( y2-y1)/(x2-x1)

    = (89-23)/(30-0)

   66/30

   =2.2 % per minute

To get to full change we need 100-23 = 77 %

77% * 1 minute/ 2.2 % =35 minutes

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.