Q3. 15x³y⁵+10x⁵y² ÷5x²y =
1. 3xy⁴ + 2x³y
2. 2x⁵y³ +5xy
3. 3x³y³+2xy
4. 5xy³+3x⁴y²
Answers
Answer:
Add the following:
(i) 3x and 7x
(ii) −5xy and 9xy
ANSWER:
We have
(i) 3x + 7x = (3 + 7)x = 10x
(ii) -5xy + 9xy = ( -5 + 9)xy = 4xy
Page No 7.13:
Question 2:
Simplify each of the following:
(i) 7x3y + 9yx3
(ii) 12a2b + 3ba2
ANSWER:
Simplifying the given expressions, we have
(i) 7x3y + 9yx3 = (7 + 9)x3y = 16x3y
(ii) 12a2b + 3ba2 = (12 + 3)a2b = 15a2b
Page No 7.13:
Question 3:
Add the following:
(i) 7abc, −5abc, 9abc, −8abc
(ii) 2x2y, − 4x2y, 6x2y, −5x2y
ANSWER:
Adding the given terms, we have
(i) 7abc + (- 5abc) + (9 abc) + (- 8abc)
= 7abc - 5abc + 9abc - 8abc
= (7 - 5 + 9 - 8)abc
= (16 - 13)abc
= 3abc
(ii) 2x2y + (- 4x2y) + 6x2y + (- 5x2y)
= 2x2y - 4x2y + 6x2y - 5x2y
= (2 - 4 + 6 - 5)x2y
= (8 - 9)x2y
= -x2y
Page No 7.14:
Question 4:
Add the following expressions:
(i) x3−2x2y+3xy2−y3, 2x3−5xy2+3x2y−4y3
(ii) a4−2a3b+3ab3+4a2b2+3b4,−2a4−5ab3+7a3b−6a2b2+b4
ANSWER:
Adding the given expressions, we have
(i) x3- 2x2y + 3xy2- y3+ 2x3- 5xy2 + 3x2y- 4y3
Collecting positive and negative like terms together, we get
x3+ 2x3- 2x2y + 3x2y + 3xy2- 5xy2 - y3 - 4y3
= 3x3 + x2y - 2xy2 - 5y3
(ii) (a4- 2a3b + 3ab3 + 4a2b2 + 3b4) + (-2a4- 5ab3 + 7a3b - 6a2b2 + b4)
a4- 2a3b + 3ab3 + 4a2b2 + 3b4 - 2a4- 5ab3 + 7a3b - 6a2b2 + b4
Collecting positive and negative like terms together, we get
a4 - 2a4 - 2a3b + 7a3b + 3ab3 - 5ab3 + 4a2b2 - 6a2b2 + 3b4 + b4
= - a4 + 5a3b - 2ab3 - 2a2b2 +