Question

1. Consider the system of equations.
x-5y=2
3x-10y=11
(a) Jamar rewrote the first equation as –2x + 10y = –4. What justification did he have for doing this?
(b) Jamar combined the equation in Part (a) with the second equation in the system to get x = 7. Explain Jamar’s reasoning.
(c) What is the solution of the system?
(d) How do you know, without graphing, that the graph of 4x – 15y = 13 passes through the point whose coordinates are the solution of the system?

Answer 1

hello

Answer 2

@freemap Compare the equation in part a with the first original equation.

Original first equation: x - 5y = 2
Equation from part a: –2x + 10y = –4

What do you do to x to become -2x?
What do you do to -5y to become 10y?
What do you do to 2 to become -4?
All questions above have the same answer. What is it?

Answer 3

please hold

Answer 4

@mathstudent55 same answer so add

Answer 5

No.
Adding won't do it.
There is no single quantity you can add in those three cases that will work.
Try multiplication.

Answer 6

Yes, multiplication because 3(5y+2)

Answer 7

Where did you get that from?

Answer 8

What do you do multiply x by to get -2x?
What do you do multiply -5y by to get 10y?
What do you do multiply 2 by to get -4?
All questions have the same answer.

Answer 9

3(5y+2)-10y=11
5y=5
y=1

Answer 10

You're using the substitution method, but this problem is not about substitution.

Answer 11

@mathstudent55 multiplying by 2

Answer 12

@jdoe0001

Answer 13

@KamiBug

Answer 14

@retirEEd

Answer 15

@rebeccaxhawaii

Answer 16

@jhonyy9

Answer 17

@jigglypuff314

Answer 18

I need part D @jdoe0001

Answer 19

I need part D @jhonyy9

Answer 20

ok. what is your opinon ,any idea about part D. ?

Answer 21

what mean eaxctly solution of a system ?

Answer 22

right.. what is the solution you've got from part 7c?

Answer 23

so, you're doing part D, so... we assume part 7c is already done

Answer 24

yes only need part D

Answer 25

@jhonyy9