Page 164 - Mathematics

Example 6.32

Solve graphically the following system of simultaneous equations.
y
x += 1 and x − 3y = 3
Solution
y
The x and y-intercepts for x += 1 are (1, 0) and (0, 1), respectively. Also,
x and y-intercepts for x − 3y = 3 are (3, 0) and (0, − 1) , respectively.
Use the intercepts to draw the graphs as shown in the following figure.

y
Tanzania Institute of Education

2

1
x+y=1
x-3y=3
-2 -1 0 1 2 3 4 x

-1
1 1
S 1 , −
-2 2 2

-3

1
1
1
The two lines intersect at the point S   1, − 1   . Therefore, x = 1 and y = −
 2 2  2 2
is the solution of the given system of linear simultaneous equations.

Example 6.33
Mathematics Form One is 18. Find the numbers graphically. ) 18.=
The average of two numbers x and y is 7 and three times y subtracted from x

Solution
Let x and y be the numbers. It follows that, the average of two numbers is

y
x +
7 and three times when y is substracted from x is 3(x y−
=
2

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25/10/2024 09:52:04
Mathematics form 1.indd 158 25/10/2024 09:52:04
Mathematics form 1.indd 158