Question

Medal
Solve the following system of equations by any method.

x + y = 32
x + z = 39
y + z= 47

Answer 1

which method u prefer to use

Answer 2

addition

Answer 3

what i meant was elimination , substitution ... matrix

Answer 4

substitution

Answer 5

Subtract the 2nd from the 1st to get y-z=-7

Answer 6

Then you'll have :
y-z =-7
y+z=47

Add the equations together to eliminate z then solve for y.

Answer 7

That's the easiest approach here.

Answer 8

y = 0 z = 0

Answer 9

-7 + 47 = 40

Answer 10

You should have gotten 2y=40 not y=0

Answer 11

oh sorry i subtracted

Answer 12

Yes I know. Be careful

Answer 13

whats the next step

Answer 14

@LynFran do you understand this

Answer 15

here ur substitution method and yes i know all 3 method thats y i ask which u prefer
ok we can rewrite the 3rd equation as y=47-z
we can also rrewrite the 2nd equation to get x=39-z
now subs the 2 equations about into the 1st equation to get
x+y=32
39-z+47-z=32
86-2z=32
86-32=2z
54=2z
27=z
now sub z=27 into the 3rd equation above to get
y+z=47
y+27=47
y=47-27
y=20

now sub y=20 into 1st equation to get
x+y=32
x+20=32
x=32-20
x=12

Answer 16

Elimination is the simplest and most efficient method to Use here.

Answer 17

yea i agree but @harz360 prefer substitution

Answer 18

The goal is to solve using the least amount of steps

Answer 19

when i see all the steps thats when i understand it

Answer 20

It's a matter of efficiency not preference.

Answer 21

I would have taken the first 2 equations...and eliminated the x's...then go from there

Answer 22

me too

Answer 23

Exactly .

Answer 24

but thanks a lott @LynFran

Answer 25

@Hero thanks so much

Answer 26

here the elimination method
using 1st and 2nd equation subtract we get
y-z=32-39
now using the 3rd equation subtract
y-z=-7
y+z=47
we get -z-z=-7-47
-2z=-54
z=-54/-2
z=27

now sub z=27 into 3rd equation we get
y+z=47
y=47-27
y=20

now sub y=20 in 1st equation we get
x+y=32
x+20=32
x=32-20
x=12

Answer 27

this method seems confusing by the subtraction method seems easier to follow

Answer 28

That WAS the subtraction method. Lyn just wrote it awkwardly

Answer 29

ohh i c

Answer 30

no thats the elimination method in details

Answer 31

Subtraction/Elimination Method

Answer 32

Interchangeable description

Answer 33

ohh i understand both when i see the steps which lyn has shown nicely