# Math

How do I solve these problems, I really need help.

Solve by substitution method

6x+5y=17
x=53-8y

Solve by elimination method

2x+3y=5
4x+6y=10

1. 👍
2. 👎
3. 👁
1. Substitution method:

6x+5y=17
x=53-8y

Solve for a variable and substitute it in to one of the equations. The easiest way with these two equations is to take x from the second equation and substitute it in to the first equation.

6(53-8y)+5y = 17

618 - 48y + 5y = 17
-48y + 5y = 17 - 618
-43y = -601
y = -601/-43

Then you plug y in to one of the equations and solve for x.

x = 53 - 8*(601/43)

Elimination method: The idea is you multiply one equation by a constant so either x or y has the same coefficient as the x or y in the other equation.

Example:

#1) x + 3y = 4
#2) 5x + 2y = -19

We need to pick a variable to eliminate. The easiest way is to eliminate the x in the second equation. To do this we multiply the first equation by 5 and subtract it from the second.

5*(x+3y) = 5*4
5x+15y = 20

It's tricky to write out the next part online, you normally write the equations directly over each other with a subtraction sign.

5x + 2y - 5x - 15y = -19 - 20
-13y = -39

At this point you can easily solve for y.

y = -39/-13 = 3

Then substitute y=3 in to one of the first equations.

x + 3y = 4
x + 3*3 = 4
x + 9 = 4
x = 4 -9
x = -5

--The problem you gave is slightly different.

2x+3y=5
4x+6y=10

In this problem you'd multiply the first equation by 2 and subtract it from the second. The new second equation is then 0 = 0.

This set of equations is not solvable. Using the elimination method one of the equations is completely eliminated because they are equivalent equations.

1. 👍
2. 👎
2. how do you do this equation by using elimination.? 8x-5y=11
4x-3y=5

1. 👍
2. 👎

## Similar Questions

1. ### How do I do this.?(Math.)

Use the Substitution method to solve the system of equations. y - 2x = -5 3y - x = 5 Solve one of the equations for x or y. Let's solve the first one for y: y - 2x = -5 y = 2x - 5 Now let's substitute 2x - 5 for y in the second

2. ### Substitution Method in Algebra!HELP PLZ!

Use the Substitution method to solve the system of equations. 3x + y = 5 4x - 7y = -10 multiply first equation by 4 multiply second equation by 3 thus both equations have same x or y value in this case it is the x value. 12x + 4y

What advantages does the method of substitution have over graphing for solving systems of equations? Choose the correct answer below. A. Graphing cannot be used to solve dependent or inconsistent systems due to the nature of the

4. ### Pre-Calc

Solve the system of equations using either the substitution method or the multiplication/addition method answer: 3x+2y=14 2x-4y=4

1. ### math

What is the first step in solving the linear system {2x−3y=11 {−x+5y=−9 by the substitution method in the most efficient way? A. Solve the first equation for x. B. Solve the first equation for y. C. Solve the second equation

2. ### algebra

x+3y=-10 7x-5y=34 solve using substitution method

3. ### Algebra

If 2x + 2y = 20 & 5x - 3y = 15 Solve using the substitution method.

1. ### Algebra

Use the substitution method to solve -x + 3y=24 5x +8y=-5

2. ### Algebra

x-2y=.9 4x-3y=13.1 Solve using the substitution method.

3. ### Algebra

solve using substitution method 3x-5y=61 3x-y=17

4. ### Math

Solve by eliminnation methods 2x-4y=5 2x-4y=6 solve the system by elimination method 5x+2y= -13 7x-3y=17 Solve x+64 Determine whether the given numbers are solutions of the inequality 8,-10,-18,-3 y-8>2y-3 Solve by the