Determine whether *y *varies directly with *x, *if so, find the constant of variation of *k* and write the equation.

x | y |

7 | 11 |

8 | 13 |

9 | 15 |

10 | 17 |

Can you show steps too!

Paypay Oct 13, 2015

#1**+5 **

Notice that, when y changes by 2, x changes by 1.......so the "constant of variation" is just the slope which is : change in y / change in x = 2/1 = 2

So.....using the point (7, 11) and the slope....we can write the general equation using the slope-intercept form as :

y =(2)(x - 7) + 11 simplify

y = 2x - 14 + 11

y = 2x - 3

CPhill Oct 13, 2015