Question

How Would I Solve The Systems " q-2r=4 " And " q+r=37 " ?

Answer 1

which method do you prefer?

Answer 2

Substution .

Answer 3

i perfer elimination; easier on the eyes :)

Answer 4

whats your sub then?

Answer 5

Well We Can Do Elimination , Either One Is Fine , I'm Just Not Sure Which Or What Way Too Start .

Answer 6

which is moot, they are both the same method just different paths :) lets do elimination so I can show you its finesse

Answer 7

q - 2r = 4
q + r = 37 <-- notice that if we get this to be a +2r, it eliminates with the top

Answer 8

q - 2r = 4
q + r = 37 <-- *2

q - 2r = 4
2q + 2r = 74
------------- ; now we add em up
3q = 78 ; divide out the 3

q = 78/3

Answer 9

simplify as wanted

Answer 10

q - 2r = 4
q + r = 37 <-- notice now that when this is -q, the qs cancel

Answer 11

q - 2r = 4
q + r = 37 <-- *-1

q - 2r = 4
-q - r = -37
----------- ; add em up
-3r = -33 ; divide off the -3

r = -33/-3 ; reduce as wanted

Answer 12

Wait , Where Did They " 2q " Come From ?

Answer 13

we use the properties of equations that tells us we can scale an equation to change its form, and it retains its same value

Answer 14

(q + r = 37) 2 , we can multiply by 2 right?

2q + 2r = 74 is an equaivalent statement that has the same inherent value

Answer 15

only now we can use it to our advantage

Answer 16

Now I See , I Just Had Too Reread It .

Answer 17

those answers reduce, so make sure you do that or else someone grading it might get upset :)

Answer 18

you have any questions?

Answer 19

So I Could Use Either 1 Or 2 To Multiply By And Still Get The Same Answer , Or No ?

Answer 20

you can multiply by whatever number you want, but in the end you want something that is useful to you to use.

sometimes you might need to mulitply the top and bottom equations by different numbers to get the to match up

Answer 21

it takes practice to notice your easiest options; but in the end, you can brute math it dragging and kicking it all the way and still come out smelling like roses

Answer 22

So I Stayed With The #2 And Multiplied , So I Got " Q=26" Which Equation Would I Use To Plug It Back In ? Too Check MySelf .

Answer 23

either one; q = q = q = q so it doesnt matter :)

id go with the q+r = 37 tho since its just simpler looking

Answer 24

11 ?

Answer 25

that is correct, good job!!

Answer 26

im out of stickers but i got these: ♫♫♫

Answer 27

Cool , Thanks But I Have Many More Problems That I Don't Know How To Do Or Really UnderStand , Can You Help Me With Them Too ?

Answer 28

post them to the left so others can spot them and help out; i gotta be going to class soon

Answer 29

Alright , Thanks .