Question

say all the answers please ​

Answer 1

Answer:

8) (a)²-(b)² = (a+b)(a-b)

and (a+b)² = a²+2ab+b²

(6.4+5.4)(6.4-5.4)

--------------------------

(8.9+1.1)²

(11.8)(1)

------------

(10)²

11.8/100 = 0.118

9) x-1/x = 2

squaring on both sides

(x-1/x)² = 2²

x²+1/x²-2(x)(1/x) = 4

x²+1/x²-2 = 4

x²+1/x² = 6

again squaring on both sides

(x²+1/x²)² = 6²

x^4+1/x^4 -2(x^4)(1/x^4) = 36

x^4+1/x^4 = 38