Y=-3x-2
subsitute -3x-2 for y
-7x+3(-3x-2)=10
distribute
a(b+c)=ab+ac
3(-3x-2)=-9x-6
-7x-9x-6=10
add like terms
-16x-6=10
add 6
-16x=16
multiply -1
16x=-16
divide 16
x=-1
subsitute
y=-3x-2
y=-3(-1)-2
y=3-2
y=1
x=-1
y=1
(x,y)
(-1,1)
Andy bought 21 packs. Harry bought 12 packs. Erin bought 21 packs.
94 seats
There are 2 ways to do this one:
1. 18 x 3 = 54
54 + 40 = 94
2. 40 + 3 + 3 + 3.... and so on.
Let me know if this was helpful!