which of the following points are solutions to the system of inequalities shown below . check all that apply ( can be multiple answers ) y5x-2 y

Question

which of the following points are solutions to the system of inequalities shown below . check all that apply ( can be multiple answers )

y>5x-2
y<5x+3

a) (4,23)
b(4,20)
c(-5,25)
d ( 5,28)

anonymous · Answer

thats what my com says up there .-. ill screen shot it hold on

anonymous · Answer

attachment

phi · Answer

when x is 4, what are the upper and lower limits on y ?

use
y>5x-2
y<5x+3

with x replaced by 4

phi · Answer

in other words,  simplify
y > 5*4 -2 
what do you get ?

anonymous · Answer

y>20-2

phi · Answer

and 20-2 is ?

anonymous · Answer

18

phi · Answer

so y > 18  (which means y is bigger than 18)
now do the other limit
y<5x+3 with x=4

y < 5*4 + 3

anonymous · Answer

y<20+3 which is 23

phi · Answer

right, which means  that when x is 4, the y value must be 18 < y < 23
(between 18 and 23)

do any of the points listed in your choices match that condition ?

phi · Answer

choice A  is point (4,23)  .  Its y value is 23.  But we need y to be LESS than 23 (not less than or equal)  so Choice A is wrong.

anonymous · Answer

d is right

phi · Answer

Did you calculate the allowed y's for when x is 5 ?

anonymous · Answer

ok wait the answers up there^ and on my computer is in different order  .-. sorru bout that

phi · Answer

look at   y < 5x +3  when x is 5
you get  y < 5*5 +3  
y < 25 + 3
y<28

but the point D (5,28)  has a  y value of 28.  28 is not LESS than 28

phi · Answer

what is choice d on your computer ?

anonymous · Answer

A. (5, 28) 
   B. (4, 20) 
   C. (-5, 25) 
   D. (4, 23)

phi · Answer

what is the y value of choice D ?

phi · Answer

the y value of (4,23) is the second number.

anonymous · Answer

23

phi · Answer

we figured out 
18 < y < 23
in other words, the y value must be bigger than 18:   23 is bigger than 18.  that is ok

but y must be less than 23

is 23 less than 23 ?

anonymous · Answer

no

phi · Answer

try a different choice.  remember, when x is 4 you want the y value between 18 and 23

anonymous · Answer

hm?

phi · Answer

Do you understand that (4,23) is not the answer because its y value of 23 does not fit between 18 and 23 ?

what choice has x=4  and its y value is between 18 and 23 ?

anonymous · Answer

b ( 4.20)?

phi · Answer

is 20 bigger than 18 ?
is 20 less than 23 ?
if so, then (4,20) is allowed

anonymous · Answer

yes c:

anonymous · Answer

thank you c:

phi · Answer

yw