Question

11 Solve the following using the appropriate
identities.
A. 19 - h)²
B. (a + 3)(a - 3)
C. (3x + y)²
D. (4y + 5)(4y + 5)
F. 103²– 97²
E. 204²​

Answer 1

Answer:

A.(19-h)²

Using the identity:-(a-b)²=a²-2ab+b²

a=19, b=h

=(19)²-2(19)(h)+(h)²

=361-38h+h²

=h²-38h+361

B.(a+3)(a-3)

Using the identity:-(a+b)(a-b)=a²-b²

a=a, b=3

=(a)²-(3)²

=a²-9

C.(3x+y)²

Using the identity:-(a+b)²=a²+2ab+b²

a=3x, b=y

=(3x)²+2(3x)(y)+(y)²

=9x²+6xy+y²

D.(4y+5)(4y+5)

=(4y+5)²

Using the identity:-(a+b)²=a²+2ab+b²

a=4y, b=5

=(4y)²+2(4y)(5)+(5)²

=16y²+40y+25