Question

Solve the system by substitution.
2x - y + z = -4
z = 5
-2x + 3y - z = -10

Answer 1

@findme can u help with this one?

Answer 2

First plug z in your equations. Because it is given.

Answer 3

To make it easy on your self, go ahead and substitute for the z as it is a 5 getting.
2x - y =-9
-2x + 3y =-5.

Answer 4

Too bad the problem requires substitution as it is ideal to solve using elimination method.

Answer 5

z=5
Substitute this in ur first equation
2x-y+z=-4
2x-y+5=-4
2x-y=-4-5
2x-y=-9
Similarly substitute z=5 in ur third equation
-2x + 3y - z = -10
-2x+3y-5=-10
-2x+3y=-10+5
-2x+3y=-5
Nw u have two equations
2x-y=-9-(1)
-2x+3y=-5-(2)
From equation (1)
u get
y=2x+9
substitute that in equation (2)
-2x+3(2x+9)=-5
-2x+6x+27=-5
Solve for x.
Then substitute the value of x in y=2x+9 to find y.

Answer 6

To use the substitution method, solve for x or y . Lets solve for x.
Using the equations radar used. (these are your original ones with z plugged in and simplified)

Answer 7

how do i find x?

Answer 8

these are the answers i have

(–8, 7, 5)
(–8, –7, 5)
(8, –7, 5)
(–8, –7, –5)

Answer 9

-2x+6x+27=-5
using this equation can u find x?

Answer 10

i got -6.2 do i round it to -7?

Answer 11

i dnt thnk u will get that answrr when u solve it. can u plz show me your work @algebra2sucks?

Answer 12

i don't think i did it right cause all i did was add them all up and divide it by -5?

Answer 13

-2x+6x=4x
-5-27=-32
4x=-32
x=-32/4
=-8
Getting this @algebra2sucks?

Answer 14

yes

Answer 15

would it b -8, 7,5

Answer 16

we know that x=-8 and z=5. to find y let us substitute the value of x in y=2x+9.
y=2*-8+9
=-16+9
y=-7

Answer 17

Do u understand this @algebra2sucks?

Answer 18

oh ok so -8, -7, 5

Answer 19

yup:)