6. Ziad has 26 money bills in his
bank, some are 500 L. L. bills and
some are 1000L. L. bills.
How many of each does he have if
he has a sum of 16 500L. L. in all?
Please can you solve this, it's about the lesson the system of equations.

1000 bills = 7

500 bills = 19

Step-by-step explanation:

x=number of 1000 bills

y= number of 500 bills

(you can even invert them, no problem)

the system is

x + y = 26

1000x + 500y = 16500

therefore

x=26-y

using this value in the next equation

1000*(26-y) + 500y = 16500

26000 - 1000y + 500y = 16500

-500y = - 9500

y=9500/500= 19

x=26-19= 7

i dont know men

step-by-step explanation:

{x = -1/2 ,   y = -1

step-by-step explanation:

solve the following system:

{2 x + y = -2

{10 x - 3 y = -2

in the first equation, look to solve for y:

{2 x + y = -2

{10 x - 3 y = -2

subtract 2 x from both sides:

{y = -2 x - 2

{10 x - 3 y = -2

substitute y = -2 x - 2 into the second equation:

{y = -2 x - 2

{10 x - 3 (-2 x - 2) = -2

10 x - 3 (-2 x - 2) = (6 x + 6) + 10 x = 16 x + 6:

{y = -2 x - 2

{16 x + 6 = -2

in the second equation, look to solve for x:

{y = -2 x - 2

{16 x + 6 = -2

subtract 6 from both sides:

{y = -2 x - 2

{16 x = -8

divide both sides by 16:

{y = -2 x - 2

{x = -1/2

substitute x = -1/2 into the first equation:

{y = -1

{x = -1/2

collect results in alphabetical order:

answer:   {x = -1/2 ,   y = -1