Chapter 4: Simple Equations

Solution:-

Consider the given equation, (9/5)x = (18/5)

By cross multiplication x = (18/5) × (5/9)

= (18/9)

= 2

Then, the value of x = 2

Solution:-

Consider the given equation, 3 – x = -4

Transpose –x to RHS then it becomes x and – 4 to LHS then it becomes 4,

3 + 4 = x

x = 7

Then, the value of x = 7

Solution:-

Consider the given equation, x – ½ = – ½

Transpose – ½ to RHS then it becomes ½

x = – ½ + ½

x = 0

Then, the value of x = 0

Solution:-

Consider the given equation, (1/6) – x = 1/6

Transpose – x to RHS then it becomes x and 1/6 to LHS then it becomes – 1/6

x = 1/6 – 1/6

x = 0

Then, the value of x = 0

Solution:-

Given 10 less than a number is 65

Then, the equation will be x – 10 = 65

Transpose, – 10 to RHS then it becomes 10

x = 65 + 10

x = 75

Solution:-

Let us assume the number be x.

If a number is increased by 20 = x + 20

If a number is increased by 20, it becomes 45, x + 20 = 45

Transpose, 20 to RHS then it becomes -20.

x = 45 – 20

x = 25

Solution:-

Let us assume the number be x.

If a number is increased by 12 = x + 12

If a number is increased by 12, it becomes 84, x + 12 = 84

Transpose, 12 to RHS then it becomes -12.

x = 84 – 12

x = 72

Solution:-

Consider the equation, x – (7/8) = 7/8

Transpose, -7/8 to RHS then it becomes 7/8.

Then, x = (7/8) + (7/8)

x = (14/8) [divide by 2]

x = 7/4

In Questions 49 to 55, state whether the statements are True or False.

Solution:-

True.

Consider the equation, 3x + 2 = 17

Transpose 2 to RHS then it becomes – 2.

3x = 17 – 2

3x = 15

x = 15/3

x = 5

Solution:-

False.

Consider the equation, 4x – 1 = 8

Transpose -1 to RHS then it becomes 1.

4x = 8 + 1

4x = 9

x = 9/4