Question

please solve all the sums as fast as possible , I will mark you as BRAINLIEST ​

Answer 1

Answer:

1.s+t =12

》s=12-t ......(1)

s-t=8

》12-t-t=8 ( put value of s from (1) )

》12-2t=8

》 2t=12-8

》2t=4

》t=2

from (1)

s=12-t

s=12-2=10

now, st= 10×2=20

s²t²= 100×4= 400

2.adding both the equations we get

x + y =5

x - y = 1

______

2x = 6

x = 3

replacing value of x in equation

x + y = 5

3 + y = 5

y = 2

putting the two values in the req eq

8xy(x2 + y2)

8(3)(2)[9 + 4]

48 * 13

= 624

3. x+y = 9----(i)

   x-y= 1 ------(ii)

adding both

2x=10

x= 5

y=4

x^2+y^2/2xy

=25+16/2(20)

51/40

4.10 AND 8 SQUARE DIFFERENCE B/W

(10)^2 - 8^2

==> 100-64

==> 36

6.2(4x^2+25y^2)

2{(2x)^2+(5y)^2}-

(2x+5y)^2+(2x-5y)^2

7.The Difference of Two Squares theorem tells us that if our quadratic equation may be written as a differencebetween two squares, then it may be factored into twobinomials, one a sum of thesquare roots and the other adifference of the squareroots. This is sometimes shown by the expression A² - B² = (A + B) (A - B).