## Elementary Algebra

a) $19.61$ miles per hr b) $38.18$ miles per hr c) $39$ times faster d) $23.8$ times faster
a) Subtract the faster speed with the slower speed. In this case, we subtract the speed of the quarter horse with the speed of a human human. $= 47.5 - 27.89$ $= 19.61$ miles per hr b) Subtract the faster speed with the slower speed. In this case, we subtract the speed of the greyhound by the speed of a spider. $= 39.35 - 1.17$ $= 38.18$ miles per hr c) Let $x =$ how many times faster the spider is. We multiply the speed of the garden snail by $x$. $0.03x = 1.17$ $x = \frac{1.17}{0.03}$ $x = 39$ times faster d) Let $x =$ how many times faster the human is. We multiply the speed of the spider by $x$. $1.17x = 27.89$ $x = \frac{27.89}{1.17}$ $x = 23.8376...$ times faster $x \approx 23.8$ times faster