New Position?

Question

 A snake lying in the sun can be modeled by the equation y=5x +7. as the afternoon progresses the snake movees 3 units up and 2 units right which of the following equations models his new position

Answer 1

You didn't give the options, but I"ll take a guess

 

Since he's moved 2 units right, we need to modify the x by 2. Likewise, we have to modify the y-intercept by 2.

 

y=5(x-2)+9

 

Let's do the y-intercept first since it's the easiest to understand. It's up 2, so we add a positive 2.

 

y=5x+7+3

y=5x+10.

 

Now we have the x to deal with. It's a little trickier to get the hang of, but not too hard.

 

now, you instinctively want to say x+2 since he moved 2 to the right but that's incorrect. we want to put in the opposite sign into the equation.

 

y=5(x-2)+10

 

Since you didn't give the options for your question, it's also possible that the answer looks like this

 

(y+3)=5(x-2)+7

 

 

Answer 2

Currently you have y = 5x+7,

 

we want to move up three and right two, first lets move up three

 

 

y = 5x + 7 + 3 = 5x + 10

 

We added three to the 7 because that is the y-intercept and moving up or down three is dependent on the y intercept,

 

next to move to the right two units

 

 

y = 5(x-2) + 10 

 

We replaced 'x' with 'x-2', this is what we do when we shift to the right. If we wanted to shift left we would have done 'x+2'. 

 

so now we have y = 5x - 10 + 10 = 5x

 

Finally, we have y = 5x as our new equation