so let’s start of by setting variables for buses and vans
x = buses
y = vans
our equations will look something like this :
4x + 14y = 742 &’
4x + 6y = 350
let’s solve for y first . we need to cancel out our x’s so we turn on of them into a negative and since both of them have the same common factor we don’t need to find it . let’s multiply the bottom equation by ( -1 )
here’s what our new equations look like :
4x + 14y = 742
-4x - 6y = -350
now that our x’s are cancelled out we add our y’s and our totals :
14y + ( -6y ) = 8y
742 + ( -350 ) = 392
we want y alone so we divide :
392/8 = 49
y = 49
now we can substitute 49 for y :
4x + 14 ( 49 ) = 742
4x + 6 ( 49 ) = 350
we can multiply those numbers together :
4x + 686 = 742
4x + 294 = 350
now we add downward :
8x + 980 = 1,092
we need x alone so we subtract 980 from both sides :
8x = 112
divide by 8 :
x = 14
now , we can substitute 14 for x and 49 for y to check our work :
4 ( 14 ) + 14 ( 49 ) = 742
742 = 742 ✅
4 ( 14 ) + 6 ( 49 ) = 350
350 = 350 ✅