Question

please help me out for this​

Answer 1

Step-by-step explanation:

Q.3) 1) D = -8 5 = (-8)×(-5) - (-8)×5

= 40 +40

-8 -5 = 80

D = 80

2 ) Given equation is 3y= 8x -2

i.e 3y - 8x = -2

-8x + 3y = -2

-8x+3y+2 =0

comparing equatoin with axsq+ bx+c=0

Here a= -8 , b = 3 , c =2

Q.4) 1) 2 - 3 = 15 , 8 + 5 = 77

x y x y

Let 1/ x be a and 1/y be b

So equations become

2a-3b=15 ........ (1)

8a+5b=77 .......... (2)

Multiply equation (1) by 4

8a - 12b = 60 ......... (3)

Subtracting equation (3) from (2)

8a+ 5b=77

- 8a-12b=60

- + -

17b = 17

b= 17/17

b= 1

Put b=1 in equation (1)

2a- 3(1) =15

2a-3 = 15

2a = 15 + 3

2a = 18

a = 18/2

a = 9

but a= 1/x and b= 1/y

9 = 1/x and 1= 1/y

9x= 1 and y = 1

x =1/9 and y=1