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Clear the fractions by multiplying both sides of the equation by the
lowest common multiple of the denominators. Then solve the equation for
the unknown by performing the same operation on both sides of it.
Example 17
Solution:
Lowest common multiple of 4 and 1 is 4. So, we multiply both sides by 4
to obtain:
Example 18
Solution:
Lowest common multiple of 10 and 15 is 30. So, we multiply both sides
by 30 to obtain:
Example 19
Solution:
Lowest common multiple of 4 and 3 is 12. So, we multiply both sides by
12 to obtain:
Problem Solving
Linear equations are used to solve practical problems. The
unknown quantity is represented by a suitable pronumeral (i.e. letter);
and then the information given in the problem is translated into an
equation which is solved as explained in the previous sections.
Example 20
If one-third of a certain number is added to one-half of the same
number, the result is 15. Find the number.
Solution:
Let x be the number.
We are given that:
The lowest common denominator of 3, 2 and 1 is 6. So, we multiply both
sides by 6 to obtain
So, the number is 18.
Key Terms
pronumeral |
