Iwill mark !

if 888x + 889y = 890 and 891x + 892y = 893, what is the value of x - y ?

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i will mark !

-3

Step-by-step explanation:

First you subtract the first equation from the second one and you get:

3x  + 3y   =  3

x +  y   =  1  

y =  1 - x

Then you use it on the first equation

888x  +  889 (1 - x)  =  890

888x  +  889  -  889x  =  890

-x = 1

x = -1

y = 1 - x

y = 1 - (-1) = 2

Now that you have those two numbers, we have to subtract the value of x from y:

x - y

-1 - 2 = -3

Hope this helps bro

5 weeks

Step-by-step explanation:

In order to solve for the amount of time it would take for both you and your brother to reach the same amount in savings, you need to set up an expression for each person.  You save $15 a week plus you start with $75, so:

You: 15x + 75

Your brother only saves $6 a week, but starts with $120, so:

Brother: 6x + 120

If 'x' is the number of weeks in both equations, we can set the expressions equal to each other to find out how many weeks until both of your accounts are equal:

15x + 75 = 6x + 120

Subtract '6x' from both sides: 15x - 6x + 75 = 6x + 120 - 6x or 9x + 75 = 120

Subtract '75' from both sides: 9x + 75 - 75 = 120 - 75 or 9x = 45

Divide and solve for x: 9x/9 = 45/9 or x = 5 weeks