Solve using substitution:
show work

2x + 5y = -5
x + 3y = 3

answer:

{x,y} = {-6/11,9/11}

step-by-step explanation:

[1]     2x + 5y = 3

  [2]     -x + 3y = 3

// solve equation [2] for the variable   x  

  [2]     x = 3y - 3

// plug this in for variable   x   in equation [1]

  [1]     2•(3y-3) + 5y = 3

  [1]     11y = 9

// solve equation [1] for the variable   y  

  [1]     11y = 9  

  [1]     y = 9/11  

// by now we know this much :

    x = 3y-3

    y = 9/11

// use the   y   value to solve for   x  

    x = 3(9/11)-3 = -6/11

solution :

{x,y} = {-6/11,9/11}

75 tickets have been sold so far.

step-by-step explanation:

in this question it is clearly mentioned that 45 children's tickets have been sold and this number is 60% of the total tickets sold.

now let's assume the total number of tickets sold be x.

then 60% of x = 45

⇒

⇒ x(.6) = 45

by dividing with .6 on both the sides of the equation

⇒ x = 75

therefore 75 tickets have been sold so far.