I need help on this, I don't get this

Work Shown:

Isolate y in the first equation

2x+y = 5

y = 5-2x subtract 2x from both sides

y = -2x+5

Then plug this into the other equation

-3x - 5y = 3

-3x - 5( y ) = 3

-3x - 5( -2x+5 ) = 3 replace y with -2x+5

-3x + 10x - 25 = 3 distribute

7x-25 = 3

7x = 3+25 adding 25 to both sides

7x = 28

x = 28/7 divide both sides by 7

x = 4  is the answer

Optional Section:

Use this value of x to find y

y = -2x+5

y = -2(4)+5

y = -8+5

y = -3

Then we can check our answers by plugging them into the original equations

2x + y = 5

2(4) - 3 = 5

8 - 3 = 5

5 = 5

That confirms the first equation. Repeat for the second equation

-3x - 5y = 3

-3(4) - 5(-3) = 3

-12 + 15 = 3

3 = 3

We've confirmed both equations, so (x,y) = (4, -3) is the solution to this system. This system is considered independent and consistent.

Graphing the two original equations will show that they intersect at (4, -3).

the equation for this situation is y=122+45. to solve the equation you would add 45 and 122 to get a total of 167lbs. in conclusion, grace's weight eight weeks ago was 167lbs.  

1. sometimes

2.   never

3   .08c = 7.50+.05c   250 pages

step-by-step explanation:

1.   sometimes

the theoretical probability of rolling a 1 is 1/6.   perhaps you got really lucky and never rolled a 1   in those 60 times.   your experimental probability is 0.   or perhaps you rolled a 1   20 times.   your experimental probability is 20/60 is 1/3.     it really just depends on how you rolled in that experiment.

2.   never

the probability of the event occurring is 1.   that is being 100 % sure it will happen.   that is the maximum amount of confidence we have.

3.   no customer card cost:   .08 times number of pages

customer card cost:   7.50 + .05 times number of pages

we want to find when it costs the same amount, so we will set these equal

let c = number of pages

.08c = 7.50+.05c

subtract .05c from each side

.08c-.05c = 7.5+.05c-.05c

.03c=7.5

divide each side by .03

.03c/.03 = 7.5/03

c =250  

the cost is the same at 250 pages