Question

Solve using substitution:
-2x − y + 1 = 0
2x = -13 − 3y
(1, -9)
(3, -5)
(-2, 5)
(4, -7)

Answer 1

Solve for a variable.
-2x − y + 1 = 0
-y = 2x - 1
y = -2x + 1
Substitute this back into the second equation as y.
2x = -13 − 3y
2x = -13 − 3(-2x + 1)
2x = -13 + 6x - 3
2x = -16 + 6x
4x = 16
x = 4
Plug x into the equation to solve for y.
y = -2(4) + 1
y = -8 + 1
y = -7

Answer 2

i already solved this one for you, it's (4,-7)

Answer 3

Solve using substitution:
y − 2x − 1 = 0
-4y = 6 − 8x
(1/2, 2)
(3, 1)
No solution
Infinitely many solutions

Answer 4

Let -2x-y=1. and 2x + 3y=-13.
Thus,
using substitution,
let y =-2x-1.....
becomes 2x + 3(-2x-1)=-13
therefore,
x=4.
y=-7.....

Answer 5

y = 2x +1

sub into
-4y = 6 -8x
-4(2x+1) = 6 -8x
-8x -4 = 6 -8x
the -8x's cancel
-4 does NOT = 6

so no solution.

Answer 6

Select the choice below that could be the first step in solving the following system of equations using elimination:
-4x − 10y = 3
3y − 3x − 7 = 0
Multiply the first equation by -4 and the second equation by 3
Multiply the first equation by 3 and the second equation by 10
Replace the right side of the first equation with the second equation
Write the second equation in terms of x

Answer 7

multiply the first equation by 3 and the second by 10

Answer 8

Solve using elimination:
5x − 4y − 10 = 0
-3x − 4y = -6
(-2, -5)
(2, 0)
(-6, -6)
(6, 5)

Answer 9

multiply the second equation by -1 and add 10 over to the other side in eq1

5x -4y =10
3x +4y = 6
(add)
8x = 16
x = 2

sub back in to get y

5(2) -4y = 10
10 -4y =10
(10's cancel)
-4y = 0
y = 0

(2,0)

Answer 10

Solve using elimination:
7x − 3y − 1= 0
4y − 6x = 12
(6, 2)
(7,18)
(4, 9)
(0, -1/3)

Answer 11

WHAT DO I DO

Answer 12

sorry, was gone for a bit.

Answer 13

first put all in standard form to make it easier

7x - 3y = 1
-6x + 4y = 12

next, multiply first by 4 and second by 3

28x - 12 = 4
-18x +12 = 36

add together, 12's cancel

10x = 40
x = 4

sub x's value to find y

7(4) - 3y = 1
28 - 3y = 1
27 -3y = 0
27 = 3y
y = 9

final answer (4, 9)

Answer 14

Solve using elimination:
-4y + 2x − 8 = 0
-3x + 6y = 12
Infinitely many solutions
No solution
(3, -1)
(-1, 4)