The document discusses two methods for solving systems of equations: substitution and elimination. The substitution method involves substituting a variable with a number in one equation and solving the resulting equation. The elimination method removes variables by canceling out like terms between two equations. An example of each method is provided to illustrate the process of solving systems of equations using substitution or elimination.

1. The equation is now 9(8) + 9y = 81. You multiply the 9 and the 8 since
the 9 is the coefficient and the 8 is the substituted variable. You get 72.
Now you add the like terms or subtract them. You subtract 72 from both sides
and you get 9. Since you got 9, the answer for Y is 1. Now to check, you
substitute both the 8(X) and the 1(Y) into the equation. The equation is now
9(8) + 9(1) = 81. 9(8) is 72 and 9(1) is 9. 72 + 9 gives you 81. 81 = 81. The
substitutes are correct. The answers are 8 and 1.
Elimination Method
The elimination method is a method for solving equations.
In the elimination method, you try to remove numbers and variables by
canceling them out with like terms of the same number on the other
equation set. To do so, two sets of equations must be present. An example of
the elimination method is 2x – 5y = 11 and 3x + 2y = 7. You multiply the top
top equation by -3 and the bottom equation by 2. By doing so, the 2x becomes

2. -6x and the 3x becomes 6x. The 6xs cancel out and remaining is
15y, -33, 4y, and 14. The 15y and 4y add up to make 19y and the -33 and 14
also add up. Now the equation is 19y = -19. You divide both sides by 19 and get
-1. To check, insert -1 as Y so the bottom equation is now 6x + 4(1) = 14.
You multiply the 4 and the -1 to get -4. Now it’s 6x – 4 = 14. You add 4 to
both sides and get 6x = 18. You divide both sides by 6 and get 3. So the
answers are X = 3 and Y = -1.
Conclusion
An equation is a system of numbers with variables and an equal sign to
Link two separate sets of numbers together. There are two ways to solve a
system of equation. One is the substitution method and the other is the
Elimination method. These two methods help us further our arithmetic and
Further develop better mathematical comprehension and skill.
Wing Jin Har – Class 803

4. What exactly is an equation?
An equation is a system of numbers which includes variables, and an
equal sign that links two separate equations together. For example,
2x + 5 = 7x + 9 is an equation. There are many ways in order to solve
equations. There is the substitution method and the elimination method.
Substitution Method
The substitution method is a method for solving equations.
In a substitution method, you compare two separate systems of equations
and try to substitute a variable with a number. To do so, a number for the
variable must be presented. An example of the substitution method is
9x + 9y = 81 – Where X is 8. You insert the 8 for X and the equation changes.
Equations