Question

(vii) What should be added to a² + 2ab + b2 to obtain 4ab + b??
(viii) What should be subtracted from a’ - 4a? + 5a
4a' + 5a - 6 to obtain a?
6 to obtain a2 - 2a + 12
(ix) How much x3
2x2 + x + 4 is greater than 2x3 + 73? – 5x + 6?
52​

Answer 1

hope it helps you in 1 question

Answer 2

$\Large\mathtt\green{ }\huge\underline\mathtt\red{Answer : }$

(vii)Let p be the required terma2 + 2ab + b2 + p = 4ab + b2p = 4ab + b2 - (a2 + 2ab +b2)Open the brackets4ab + b2 - a2 - 2ab - b2Now combine like terms4ab -2ab + b2 - b2 - a2= 2ab -a2Lets checka2 + 2ab + b2 + 2ab - a2Now combine like terms2ab+ 2ab + 1a2 - 1a2 + b2= 4ab + 0 + b2So the answer is 2ab.

CBSE (English Medium) Class 6

(viii) SOLUTION

Let the expression to be subtracted be X.

(a3 − 4a2 + 5a − 6)-X = (a2 − 2a + 1)

X = (a3 − 4a2 + 5a − 6)- (a2 − 2a + 1)

Since '-' sign precedes the parenthesis, we remove it and change the sign of each term within the parenthesis.

X = a3 − 4a2 + 5a − 6- a2 + 2a - 1

Rearranging and collecting the like terms:

X = a3 +(− 4-1)a2 + (5+2)a − 6 - 1

X = a3 −5a2 + 7a − 7

So, a3 −5a2 + 7a − 7 must be subtracted from a3 − 4a2 + 5a − 6 to obtain a2 − 2a + 1.

(ix) -x3-9x2+6x-2

Step-by-step explanation:

(x3-2x 2+xt4) - (2x3-7x^2-5x+6)

=x3-2x2+x+4-2x3-7x^2+5x-6

=x3-2x3-2x^2-7x*2+x+5xt4-6

=-x3-9x"2+6X-2.

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