Question

Fancy goldfish x cost $3 each and common goldfish y cost $1 each.Graph the function y=20-3x to determine how many of each type of goldfish Tasha can buy for $20.

Answer 1

The pairs of goldfish Tasha can buy for $20 are $(0,20), (1,17), (2,14),$

$(3,11),(4,8),(5,5),and (6,2)$

Step-by-step explanation:

To find the how many type of goldfish that Tasha can buy for $20 is the set of positive ordered pairs.

Let x denote the number of fancy goldfish.

Let y denote the number of common goldfish.

To find how much goldfish can Tasha buy for $20 is to substitute the value for x in the equation $y=20-3x$

Now, substituting $x=0$ in $y=20-3x$, we get,

$y=20$

The ordered pair is $(0,20)$

Similarly, substituting $x=1$,

$y=20-3(1)\\y=20-3\\y=17$

For $x=2$,

$y=20-6\\y=14$

For $x=3$,

$y=20-9\\y=11$

For $x=4$,

$y=20-12\\y=8$

For $x=5$,

$y=20-15\\y=15$

For $x=6$,

$y=20-18\\y=2$

Thus, the pairs of goldfish Tasha can buy for $20 are $(0,20), (1,17), (2,14),$$(3,11),(4,8),(5,5),and (6,2)$