Adult tickets for a charity concert were $5 each. Students were admitted for $2 each. The charity concert sold 700 tickets and made $3050. How many students attended the lecture?

students 150

adult 550

Step-by-step explanation:

x + y = 700

5x + 2y = 3050

x = 700 - y

5(700 - y) + 2y = 3050

3500 - 5y + 2y = 3050

-3y + 3500 = 3050

-3y = 3050 - 3500

-3y = -450

y = -450 / -3

y = 150

x = 700 - y

x = 700 - 150

x = 550

5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

y = mx + c ( m is the slope and c the y-intercept )

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = = -

y = - x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - + c ⇒ c = -

y = - x - ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form