2. What is System of Equations?
System of equations is a collection of two or more equations
with a same set of unknowns.
For example
I have to buy total 100 candies and chocolates for Halloween
Party.
Candy cost 10Tk for each and chocolate cost 20Tk for each.
I paid 1400Tk for candies and chocolates. How many
chocolates I got?
x + y=100
{
10x + 20y = 1400
-10x + -10y = -1000
+10x + 20y = 1400
---------------------------------
10y = 400 = 1y = 40
Candy = x
Chocolate = y
3. HOW to Solve it..?
There are two ways to solvesystem of equations.
The method of addition and subtraction
It is a way to erase one
Unknown.
2x + 3y = 8
{
2x + 7y = 16
2x + 3y = 8
- 2x + 7y = 16
-
-
- 4y = - 8
y = 2
x = 1
2x + 3y = 8
2x + 6 = 8
2x = 2x = 1
4. The method of substitution
x + 3y = 11
{
Make a equation of x or y.
And put that equation in other
Equation.
Than you can have only one
Unknown.,
2x + 7y = 25
x = 11 3y
2(11 3y) + 7y = 25
22 6y + 7y = 25
- 6y + 7y = -22 + 25
Y = 3
X = 2
x + 9 = 11
11- 9 = x
2 = x
5. If..it has more than 2
Equations;;
7x + y = 6x + 3y + 1 = 2x + 4y + 12
7x + y = 6x + 3y + 1
7x + y = 2x + 4y + 12
{
You can just divide it into2
System of equations.
Theyare all equal.
Sometimes, you can see the equations that
Has more than two equations.
6. ~Thanks for
watching~
