Page 223 - Start Up Mathematics_6

4. An equation is satisfied only for a definite value of the variable.

5. If a, b, c are three variables, then associative property of addition is (a + b) + c = a + (b + c).
Fill in the Blanks

1. The circumference of a circle in terms of its radius r is _____________.
2. A mathematical expression formed using arithmetic operations in numbers and variables is
known as _____________.
p
3. The equation 3 – 2 = 0 expressed in the statement form is “If a number is divided by
_____________ and then _____________ is subtracted from it, the result is _____________.
4. An equation is a statement in which the symbol _____________ is used.
5. Trial and error is one of the methods to obtain the _____________ of an equation.
6. Fifty reduced by one-fourth the product of nine and x in algebraic form is _____________.

Answer in One Word or a Line
1. What is Algebra?
2. How is a variable different from a constant?
3. What is an equation? How it is different from an inequality?
4. What do you mean by solution of an equation? How many solutions does a linear equation
have?
5. If cost of one pen is ` 10 and a pencil costs ` 2, find the cost of x pens and y pencils.
6. If 2x = 8, find x.

let’s evaluate

1. Observe the pattern, identify the variable and write its general expression.
Number of cows 1 2 3 4 ... n
Total number of legs 4 8 12 16 ... ...
2. Using literals, write the following in algebraic forms:

(a) Add five to a number divided by three and multiply the result by six.
(b) Two-fifth of the sum of 3x and –4y
(c) 3 times y to which 13 is added

(d) 5 times y from which 8 is subtracted
(e) y multiplied by –3 and then 7 is added to the result
(f) y multiplied by –5 and the result is subtracted from 10

3. Observe the following pattern, identify the variable and write its general expression.
4, 8, 12, 16, 20, 24, ... .
4. Observe the following pattern of polygons made with matchsticks and complete the table.
Also, write its general term.

, , , ...

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