simultaneous equations

1. Solving simultaneous
equations.
Grade 10

2. To solve two simultaneous equations
means to use both equations together
to find one value for each unkown so
that these values satisfy both
equations.

3. Steps to solve a quadratic equation.
Move all terms to the LHS leaving only a
zero on the RHS
Factorise the LSH
Use the zero-factor principle to find the
values of variables

4. Methods to solve simultaneous equations.
By elimination of one variable
By substituting
By determining the intersection point of
two graphs.

5. Example.
The sum of two resistance is 14 and their
difference is 6. Determine the two
resistances.

6. Solution
X + y =14....(1)
X-y =6
2x=20
x=10

7. Substitute x =10 into ..... (1)
10 + y = 14
y=14-10
y=4
The resistance are 10 and 4

8. Example 2
 X^2 +Y^2= 25
 Y= -3X – 5
Solution
X^2 + y^2 =25..... (1)
Y= -3x—5...... (2)

9. Substitute
Y=-3x—5
Into x^2+y^2=25
X=0 or X=-3

10. Y=-3x—5
Y=-3(0)
Y=0—5
Y=-5

11. Substitute x=-3x—5
Y=-3 (-3)—5
Y=4
(0,5) or (-3,4)

12. References
Larson R, (2014).Precalculus 9th edition,
The Pennylvania state University. Cengage
Learning.

13. Example.