Question

Can someone help me make the two equations for this table of of values?

Answer 1

Year number Western Beach width (in feet) Dunes Beach width (in feet)
0 100 20
5 90 45
10 80 70
11 78 75
12 76 80
15 70 95

Answer 2

@mathstudent55

Answer 3

@myko

Answer 4

What pattern is shown in each beach?
Between which years will they approximately have the same width?
Assuming these rates remain constant, what can you do to get a better approximation of when the two beaches will have the same width?

Answer 5

Kinda stumped on this one.

Answer 6

you know what a linear relation is?

Answer 7

I know what a linear equation is. and linear systems of equations.

Answer 8

so notice that bouth relations are linear. If you call x number of years past and y Western Beach width and z Dunes Beach width can you make the equations?

Answer 9

Don't we need to find whats happening to the original value? I've tried a few different ones but they don't give me the same numbers all the way down.

Answer 10

1º equation would be:
y=100-2x

Answer 11

can you make 2º

Answer 12

ok right, that works all the way, and the second one would beeee..

Answer 13

20 + 5x?

Answer 14

yes. Now they are asking you when the width of two beaches will be equal. That means y=z, or since we know expretions for y and z in terms of x:
100-2x=20+5x
solve this for x

Answer 15

does it matter which side we isolate x?

Answer 16

no

Answer 17

2x=-100+20+5x.... x=-50+10+5x/2?

Answer 18

100-2x=20+5x
100-20=5x+2x
80=7x
x=80/7

Answer 19

so thats our x coordinate?

Answer 20

yes

Answer 21

now what about y?