Question

Solve this by substitution method. Right answer will be marked as brainliest. Donot spam.
$(i) \: 45 - \frac{200}{20+y} = x \\ (ii) \: \frac{400}{y} = x$
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Answer 1

Answer:

Step-by-step explanation:

/* Dividing bothsides by 200, we get */

/* put y = -40 in equation in (2) , we get */

Therefore.,

Answer 2

Step-by-step explanation:

45-200/20+y =x ...(.i)

400/y=x .......(ii)

from (i) and(ii)

45-200/20+y =400/y

((20+y)45 -200) / 20+y = 400/y

(900+45y-200)y =400(20+y)

45y^2+700y=8000+400y

45y^2+300y-8000= 0

9y^2+60y-1600=0

a=9 b=60 c =-1600

60^2-4(9)(-1600)=3600+ 57600= 61200>0

9y^2+60y-1600=0 has two distinct real roots.

roots are (-b+or-root(b^2-4ac))/2a

y=(-60+ or - root(61200))/2(9)

=( -60+or- root(100×4×9×17))/18

=(-60+or- 60root17))/18

y= (-10+or - 10root17)/3

x=400/((-10+or-root17)/3)

=120/(-1+or-root17)