Question

A pair of equations is shown below:

y = 8x − 9
y = 4x − 1

Part A: Explain how you will solve the pair of equations by substitution or elimination. Show all the steps and write the solution.

Answer 1

@Data_LG2

Answer 2

Do you know what elimination and substitution method are?

Answer 3

not really

Answer 4

Substitution is when you replace one variable from the 1st equation using the 2nd equation. Elimination is when you manipulate the two equations, so that when you add those two , one variable will be eliminated.

So looking at your equations, substitution is the easiest method.
\(\sf \color{red}{y} = 8x − 9\)
\(\sf \color{red}{y = 4x − 1}\)

replace y in the 1st equation with the 2nd equation
it will be like this:
\(\sf \color{red}{4x − 1}= 8x − 9\)

dis this part clear?

Answer 5

oh ok yea now i know and then sovle right

Answer 6

x=5

Answer 7

is that right @Data_LG2

Answer 8

let's see
4x−1=8x−9
9-1=8x-4x
8=4x

hmm I don't think so..

Answer 9

x=2?

Answer 10

is that right @Data_LG2

Answer 11

yes. do you understand it though?

Answer 12

yes

Answer 13

is that the answer

Answer 14

@Data_LG2

Answer 15

are you still there

Answer 16

yes.

Answer 17

can you help me find y

Answer 18

to find y, just plug the x value that you found in any of the two equations given

Answer 19

can you help me

Answer 20

@Data_LG2 can you help me

Answer 21

choose one of the equations given

Answer 22

tell me which one you choose 1st or 2nd equation?

Answer 23

1st

Answer 24

can you help me???

Answer 25

alright. sorry i was afk

y=8x−9

x = 2 from your calculation.

replace x in the 1st equation by 2

y= 8(2) - 9

then evaluate, what will you get?

Answer 26

y=5

Answer 27

is that right @Data_LG2

Answer 28

what is 8 x 2?

Answer 29

then subtract 9 from the product of those two, what will you get?