child tickets sold= x
adult tickets sold = y
equation 1
x + y = 670
solve for y
x + y = 670
subtract x from both sides
y= 670- x
equation 2
5x + 8y =4190
plug in equation 1 into equation 2
5x + 8 (670- x)=4190
distribute:
5x + 5,360- 8x=4190
solve for x
step 1 combine like terms
5x- 8x = -3x
-3x+5,360=4190
subtract 5,360 from both sides
-3x= -1,170
divide by -3
x=390
you know x now plug it in
5 (390) + 8y=4190
1,950+8y=4190
-1950. -1950
8y=2,240
divide both sides by 8
y=280
back to original equation 1
y+x=670
plug y and x in
280+390= 670
in conclusion 280 adult tickets were sold and 390 child tickets were sold.
this was killing me
