Question

Solve the following -

a) What should be added to x 2 + xy + y 2 to obtain 2x 2 + 3xy?

b) What should be taken away from 3x 2 − 6y 2 + 4xy + 15 to obtain − x 2 − y 2 + 2xy + 12?

c) From the sum of 4x −2y + 15 and − y − 21, subtract 7x − y − 9.

d) Simplify i) ((52) 4 x 55 ) ÷ 59 ii) e) i) Compare 22.4 x 107 and 1.4 x 1010 ii) Express 729 x 64 in exponential form.​

Answer 1

Answer:

a) So, the correct answer is “ \[{x^2} + 2xy - {y^2}\] ”.

b)

Let q should be subtracted.

Then according to question,

3x

2

−4y

2

+5xy+20−q=−x

2

−y

2

+6xy+20

⇒q=3x

2

−4y

2

+5xy+20−(−x

2

−y

2

+6xy+20)

⇒q=3x

2

−4y

2

+5xy+20+x

2

+y

2

−6xy−20

⇒q=3x

2

+x

2

−4y

2

+y

2

+5xy−6xy+20−20

⇒q=4x

2

−3y

2

−xy+0

Hence, 4x

2

−3y

2

−xy should be subtracted

c) Sum of 3x-y-11 & 3x -y-11 is

⇒3x−y+11−y−11=3x−2y.

then substract 3x-y-11.

p=3x-2y-(3x-y-11)=3x-2y-3x+y+11

p=11-y.

d)