## MP Board Class 6th Maths Solutions Chapter 11 Algebra Ex 11.3

Question 1.

Make up as many expressions with numbers (no variables) as you can from three numbers 5, 7 and 8. Every number should be used not more than once. Use only addition, subtraction and multiplication.

(Hint : Three possible expressions are 5 + (8 – 7), 5 – (8 – 7), (5 × 8) + 7; make the other expressions.)

Solution:

(a) (8 × 5) – 7

(b) (8 + 5) – 7

(c) (8 × 7) – 5

(d) (8 + 7) – 5

(e) 5 × (7 + 8)

(f) 5 + (7 × 8)

(g) 5 + (8 – 7)

(h) 5 – (7 + 8)

Question 2.

Which out of the following are expressions with numbers only?

(a) y + 3

(b) (7 × 20) – 8z

(c) 5 (21 – 7) + 7 × 2

(d) 5

(e) 3 x

(f) 5 – 5n

(g) (7 × 20) – (5 × 10) – 45 + p

Solution:

(c) and (d) have expressions with numbers only.

Question 3.

Identify the operations (addition, subtraction, division, multiplication) in forming the following expressions and tell how the expressions have been formed.

(a) z + 1, z – 1, y + 17, y – 17

(b) 17y, \(\frac{y}{17}\), 5z

(c) 2y + 17, 2y – 17

(d) 7m, – 7m + 3, – 7m – 3

Solution:

(a) z + 1 = 1 added to z

z – 1 = 1 subtracted from z

y + 17 = 17 added to y

y – 17 = 17 subtracted from y

(b) 17y = y multiplied by 17

\(\frac{y}{17}\) = y divided by 17

5z = z multiplied by 5 .

(c) 2y + 17 = First y multiplied by 2, then 17 added to the product

2y – 17 = First y multiplied by 2, then 17 subtracted from the product

(d) 7m = m multiplied by 7

-7m + 3 = First m multiplied by -7, then 3 added to the product

-7m – 3 = First m multiplied by -7, then 3 subtracted from the product

Question 4.

Give expressions for the following cases.

(a) 7 added to p

(b) 7 subtracted from p

(c) p multiplied by 7

(d) p divided by 7

(e) 7 subtracted from – m

(f) -p multiplied by 5

(g) -p divided by 5

(h) p multiplied by – 5

Solution:

(a) p + 7

(b) p – 7

(c) 7p

(d) \(\frac{p}{7}\)

(e) -m – 7

(f) -5p

(g) \(\frac{-p}{5}\)

(h) -5p

Question 5.

Give expressions in the following cases.

(a) 11 added to 2m

(b) 11 subtracted from 2m

(c) 5 times y to which 3 is added

(d) 5 times y from which 3 is subtracted

(e) y is multiplied by – 8

(f) y is multiplied by – 8 and then 5 is added to the result

(g) y is multiplied by 5 and the result is subtracted from 16

(h) y is multiplied by – 5 and the result is added to 16.

Solution:

(a) 2m + 11

(b) 2m – 11

(c) 5y + 3

(d) 5y – 3

(e) -8y

(f) -8y + 5

(g) 16 – 5 y

(h) -5y + 16

Question 6.

(a) Form expressions using t and 4. Use not more than one number operation. Every expression must have t in it.

(b) Form expressions using y, 2 and 7. Every expression must have y in it. Use only two number operations. These should be different.

Solution:

(a) t + 4, t – 4, 4 – t, 4t, \(\frac{t}{4}\), \(\frac{4}{t}\)

(b) 2 y + 7, 2y – 7, 7y + 2,7y – 2 and so on.