Class 9
maths chapter 2 polynomial
it's urgent please give us answer fast
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Answers
Answer:
(x+3)2= x2 + 6x + 9
Step-by-step explanation:
using the formula (a+b)2= a^2 + 2ab + b^2
expand the given sum
i.e by substituting the value of a and b with x and 3
we get x^2+2.x.3+3^2
= x^2+6x+9
Step-by-step explanation:
1. (x+3)²
=(x+3) (x+3)
=x(x+3)+3(x+3)
=x²+3x+3x+9
=x²+6x+9
2. (x-7)²
=(x-7) (x-7)
=x(x-7)-7(x-7)
=x²-7x-7x+49
=x²-14x+49
3. (3x-2y)²
=(3x-2y) (3x-2y)
=3x(3x-2y)-2y(3x-2y)
=9x²-6xy-6xy+4y²
=9x²-12xy+4y²
4. x²-25y²
=x(x)-5y(5y)
5. (3a+4b+5c)²
=(3a+4b+5c) (3a+4b+5c)
=3a(3a+4b+5c)+4b(3a+4b+5c)+5c(3a+4b+5c)
=9a²+12ab+15ac+12ab+16b²+20bc+15ac+20bc+25c²
=9a²+16b²+25c²+24ab+40bc+30ac
6.(4a-2b-3c)²
=(4a-2b-3c) (4a-2b-3c)
=4a(4a-2b-3c)-2b(4a-2b-3c)-3c(4a-2b-3c)
=16a²-8ab-12ac-8ab+4b²+6bc-12ac+6bc+9c²
=16a²+4b²+9c²-16ab+12bc-24ac