Answer:
Step-by-step explanation:
R=r
When we say that y varies <em>directly </em>with x, we mean that whatever value x is scaled up by, y will be scaled up by, too. The simplest kind of direct variation is one where y = x for all values of x. If you multiply x by some value, y must be multiplied by that same value.
More generally, though, you'll have something of the form y = kx, where the variable k here is referred to as the <em /><em>constant of proportionality.</em> Another way you can think of k is as the <em>ratio of y to x</em>.
In this problem, you're given a set of values for x and y, and you'll need to use those to find the constant of proportionality before you set up an equation relating x to y. Substituting our general equation y = kx for the given values, we have:
-5 = k(15)
To get k, simply divide both sides by 15 to obtain:
k = -5/15 = -1/3
So, our general equation, for <em>any x</em>, would be y = (-1/3)x
Answer:
a_n = 3 + a_n − 1 a_ n = 3 + a_ n − 1
Step-by-step explanation:
The first term is 8, so a_1 = 8
Each time we want a new term, we add on 3
8+3 = 11
11+3 = 14
14+3 = 17
17+3 = 20
23+3 = 26
and so on
This recursive step of adding on 3 to the prior term is written as this: an = 3+a_n-1 which says "to get the nth term, add 3 to the term just before the nth term"