Question

29. Given that x + 2y = -2 and x - 2y = 18, find the value of
(i) x^2- 4y^2?,
(ii) x^2 + 4y^2?.​

Answer 1

Answer:

-36 and 164

Step-by-step explanation:

(i)

We know, a^2-b^2 = (a+b) (a-b)

So, (x^2-4y^2) = (x+2y) (x-2y)

= (-2)(18)

= -36

(ii)

We know, a^2+b^2 = 1/2 {(a+b)^2+(a-b)^2}

So, (x^2+4y^2) = 1/2 {(x+2y)^2 + (x-2y)^2}

= 1/2 {(-2)^2 +(18)^2}

= 1/2 (4+324)

= 328/2

= 164

Answer 2

Answer:

1.. 36

2.. 164

Step-by-step explanation: