Wednesday

October 1, 2014

October 1, 2014

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

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 - Solve each of the following systems by using either addition or ...

algebra 1 - I was just wondering if anybody could explain to me the steps in '...

math - Solve systems by substitution 5x - 2y = -5 y - 5x = 3 Substitute 5x + 3 ...

Math - Solve the systems using substitution. 1.6x + 2y = -2 4x + y = 1

algebra 2 - Nonlinear systems Solve the system by elimination. y=x^2+2 -4x-y=10 ...

algebra - i need help with these problems (either a solution or how to plug them...

Linear Equations - Can you please help solve this equation using the ...

math/algebra - Solve the following systems: 2x + 2z =2 4x + 2y =3 2× + 2y + 2z =...

math/algebra - Solve the following systems: 1) x+z=2 2x+y=3 X-y+z=1