Question

Write a system of two equations using x and y for the following problem: The sum of two numbers is 170 and their difference is 26. Find the two numbers.

Answer 1

You know to use variables?

Answer 2

ummm....yea

Answer 3

ok. im pretty you know how to do this then. what have you done so far?

Answer 4

A + B = 170
A - B = 26

Answer 5

yup

Answer 6

okay so then wat do i do next?

Answer 7

now, rearrange one of the equations to solve for either a or b.

Answer 8

ok?

Answer 9

okay so then will it be: 26+b=170?

Answer 10

idk how tor do this ;(

Answer 11

no...i dont think so...

Answer 12

take
A + B = 170.
can you isolate a for me?

Answer 13

umm...-b+170..idk

Answer 14

a=-b+170. good. now sub that into A - B = 26 (for a)

Answer 15

So then would b=144

Answer 16

i dunno. maybe?

Answer 17

wat do u mean maybe???

Answer 18

i didnt do the math myself

Answer 19

you have to divide that by 2...

Answer 20

-2.

Answer 21

and originally, it would have been -144, not 144

Answer 22

You can do all of that or you can simply add both equations together:

A + B = 170
A - B = 26
___________

2A = 192
A = 192/2
A = 96

B = A - 26
B = 96 - 26
B = 70

Answer 23

so it would be 72?

Answer 24

Well I obviously added wrong

Answer 25

yah think lol ;)

Answer 26

A + B = 170
A - B = 26
___________

2A = 196
A = 196/2
A = 98

B = A - 26
B = 98- 26
B = 72

Answer 27

Okay thnk u @hero but @NotTim cna u still help me solve the second part?

Answer 28

What second part?

Answer 29

You were only supposed to find the two numbers. A is one number. B is the other number.

A = 98
B = 72

Is there something else you need to find besides that?

Answer 30

No i need to know how to find 98 word for word

Answer 31

When solving systems of equations, there are five methods you can use:

1. Substitution
2. Elimination
3. Addition
4. Graphing
5. Slope-Intercept

Answer 32

Which method are you confused about?

Answer 33

okay this is wat i'm tlking about: how did u get 2A=196?

Answer 34

I added the two equations together.

Answer 35

The elimination method involves adding equations together to eliminate variables.

Answer 36

In this case I added A + B = 170 to A - B = 26.
When you add two equations together, you add like terms.
Therefore:
A + A = 2A
B - B = 0
170 + 26 = 196

Thus 2A + 0 = 196 or simply 2A = 196