Question

Someone PLEASE help me i've been stuck on this for days.
2. A system of equations is given below.
2x + 7y = 1
-3x – 4y = 5
1. Create an equivalent system of equations by replacing the first equation by multiplying the first equation by an integer other than 1, and adding it to the second equation.

2. Use any method to solve the equivalent system of equations (the new first equation with the original second equation).
3. Prove that the solution for the equivalent system is the same as the solution for the original system of equations.

Answer 1

@ganeshie8 @ash2326 someone?

Answer 2

Let's solve this, can you multiply the first equation by any integer other than 1 ?

Answer 3

yes, I did by 5 and got 10x+35y=5

Answer 4

Good, can you write the modified first equation and the original second equation?

Answer 5

yes 10x+35y=5 and -3x-4y=5

Answer 6

Ok, do you know any method of solving equations with 2 variables?

Answer 7

yeah

Answer 8

can you try to use it to solve these equations?

Answer 9

I'm just confused about what they're trying to tell me and I have troubles adding those type of equations together, I asked my teacher but it wasn't much help.

Answer 10

10x+35y=5 and -3x-4y=5
ok, multiply the first equation by 3 and second by 10, can you try?

Answer 11

yes one second

Answer 12

ok

Answer 13

for the first one it would be 30x+105y=15 and the second one it would be -30x-40y=50 I believe...

Answer 14

am i correct?

Answer 15

yes let's write it
as
30x+105y=15
-30x-40y=50
Can you add both the equations?

Answer 16

I don't think so :/

Answer 17

why? just add left side together and right side together, simple addition :)

Answer 18

i'll try

Answer 19

good

Answer 20

umm I got 0+65y=65

Answer 21

yes, good, can you divide both sides by 65?

Answer 22

yes it would be 1

Answer 23

so y=1?

Answer 24

are you still there

Answer 25

sorry I was afk, yes good. Can you put y in any of the equations and find the value of y?

Answer 26

in which equations

Answer 27

any of the two equations, the modified first or the original second

Answer 28

well I don't believe so...

Answer 29

try, put y=1 and solve for x

Answer 30

okay :)

Answer 31

for 30x+105y=15 I got x= -3

Answer 32

yes, correct. So we are done with 2 parts

Answer 33

really?

Answer 34

so for the first part I write the modified question and also write what the answer would be when i add them?

Answer 35

first one the modified and the original second equation
second part solving for x and y
for the third part solve the original equations to find x and y, they would come the same and you'll prove that

Answer 36

okay just to be sure... to solve the original equations i have to add them together first right?

Answer 37

no need, just multiply both of them with integers such that coefficient of x or y in both the equations is same.
2x + 7y = 1
-3x – 4y = 5

Answer 38

that kinda confused me

Answer 39

coefficents of x 2 and -3
you can multiply first by 3 and second by 2, you'll get
6x+21y=3
-6x-8y=10
you can solve by adding which will eliminate x and then you can find y
or you can multiply first by 4 and second by 7 and add them to eliminate y
anything would work

Answer 40

okayy, thank you soo much! :) i can catch back up on pace now lol

Answer 41

yeah :)