Page 88 - Mathematics

2. The difference between 123 and Solving linear equations with one
another number is 150. unknown
3. The sum of 21 and another number Solving an equation with one unknown
is 125. means finding the value of the unknown
variable which satisfy the equation. It
4. When a certain number is increased involves several steps of simplification
by 15, the result is 88. to obtain the value of the variable which
5. When 99 is decreased by a certain satisfies the given equation.
number, the result is 63.

6. The product of 12 and another number Note: Whatever operation is done
Tanzania Institute of Education
is the same as two times the sum of on the left-hand side of the
12 and the number. equation must be done on the
7. A number is such that, when it is right-hand side.
doubled and 8 is added to it, the result
is the same as multiplying the number Example 5.16
by 3, and subtracting 7.

5
8. When 36 is added to a certain number, Find the solution of x += 8.
the result is the same as multiplying Solution
the number by 5. Given x += 8.
5
9. Janeth’s mother is five times as old Collect the like terms by subtracting
as Janeth. After 8 years, her mother 5 from both sides. That is,
will be 4 times as old as Janeth. x +− 85−
55 =
10. When the sum of n and (n + 3) = 3
numbers is multiplied by 5, the result Therefore, x 3
is two times the difference between
the larger number and the smaller Example 5.17
number.
11. The sum of one-third of a number and Find the value of x that satisfies the
two-fifth of another number is 1. equation x −=
8162 .x−
Mathematics Form One 13. Four times the value of a quantity Given x −= − + 8
12. The difference between one-half of
Solution
a number and one-third of another
8162 .x−
number is 2.
Collect the like terms by performing
the following:
equals the sum of 2 and a quarter of
8 8162x+ =
x −
the value of another quantity.

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Mathematics form 1.indd 82