Posted by **Diana** on Thursday, June 7, 2007 at 12:21am.

solve each of the following systems by substitution.

16) 5x -2y = -5

y - 5x = 3

20) 8x -4y = 16

y = 2x - 4

28) 4x -12y = 5

-x + 3y = -1

Step one: Solve on of the equations for one of the variables.

y=2x-4

Step two:Substitute the expression for the variable found in step one into the other equation.

8x-4(2x-4)=16

Step three:Solve the equation from step two to find the value of one variable.

Use the distributive property

8x-4(2x-4)=16

8x-8x+16=16

x+16=16

-16 -16

x=0

Step four:Substitute the value found in step three in any equation containing both variables to find the value of the other variable.

y=2x-4

y=2(0)-4

y=0-4

y=-4

step five: check the proposed solution in the orginal system.

8(0)-4(-4)=16

0+16=16

16=16

The equation is equal, so it is correct.

#28

4x-12y=5 -x+3y=-1

+x +x

3y=-x or -3y=x

4(-3y)-12y=5 4x-12(5)=5

-12y-12y=5 4x-60=5

y=5 +60 +60

4x=65

x=65/4

4(65/4)-12(5)=5

260/4 - 60=5

65 - 60 = 5

5 = 5

it's correct

I hope I helped

## Answer This Question

## Related Questions

- algebra - Solve the following systems by substitution. 4x-12y=5 -x+3y=-1
- Algebra - How do I solve the following by substitution: 5x -2y =-5 y - 5x = 3 8x...
- Algebra 1 - solve each following system by substitution. 4x-12y=5 -x+3y=-1
- Algebra 1 - solve each following system by substitution 4x-12y=5 -x+3y=-1
- Algebra - Solve by substitution: 4x-12y =5 -x + 3y = -1
- algebra - Solve by substitution; 4x-12y=5 -x+3y
- Algebra - How to solve by substitution: 4x - 12y=5 -x + 3y = -1
- Algebra - Can someone show me step by step how to do this problem to have an ...
- math - Solve this system 4x-12y=5 ,-x+3y=-1 by substitution
- algebra - Solve each of the following systems by using either addition or ...

More Related Questions