KOLEKSI SIRI PERTAMA QUANTUM COOL-ACTIVE: MATHEMATICS SIMPLIFIED : FROM BASICS TO BRILLIANCE

KeypointsKeypoints NotesNotes

SummarySummary

LINEAR EQUATION IN TWO VARIABLE

Two main ways to solve simultaneous

equations :

1. Elimination method

5x - 8y = 45 ....(1)

9x - 8y = 49 ....(2)

Step 1 : Eliminate one of the variables.

(1) - (2) : -4x + 0 = -

x = 1

Step 2 : Substitute x = 1 into (1)

5(1) - 8y = 45

• 8y = 45 - 5
  y = -

2. Substitution method
   x - 2y = 8 ....(1)
   x + y = 5 ....(2)
   Step 1 : Let x be ALONE
   From (2), x = 5 - y ....(3)
   Step 2 : Substitute (3) into (1)
   (5-y) - 2y = 8 Step 3 : Substitute

• 3y = 8 - 5 y = -1 into (3)


• 3y = 3 x = 5 - (-1)
  y = -1 x = 6

Step by step solution :

ELIMINATION

METHOD

1.Find the same

coefficient for both

equation (if both

don’t have, can use

substitution method)

2. Eliminate one of the

variable

3. Substitute the

value of variable and

solve

SUBSTITUTION

METHOD

1.Let one of the

equation whether

has only x or y

2. Substitute the

new equation from

step 1 in other

equation then solve

LINEAR EQUATIONSLINEAR EQUATIONS

Elimination method :

ELIMINATE one of the variable

and use substitution to solve

the other variable.

Substitution method :

Let one of the equation has

only one variable to substitute

in other equation.