Louis and Tony are building houses out of blocks. Louis has 30 blocks, and gives Tony 13 blocks to build with. Which equation can be used to determine the number of blocks Louis has left to build his house with?
1.
30 - 13 = x
2.
1330 = x
3.
30-X = 13
4.
X - 13 = 30
pls help

1

Step-by-step explanation:

Since he has 30 blocks to begin with he gives 13 of them away. 30-13 is x which is your answer of 17.

there are lots of ways.   pick's theorem tells us if the vertices are lattice points the area a is

a = b/2 + i - 1

where b is the number of boundary lattice points and i is the number of interior lattice points.

in the figure i count b=16, i=50 so

a = 8 + 50 - 1 = 57

let's try the shoelace formula.   the area is half the sum of the cross products of the sides.  

a(-2,6)   -2(2)-6(-5) = 26

b(-5,2)   -5(-3) - 2(-2) = 19

c(-2,-3) -2(-3) - (-3)(4) = 18

d(4,-3)   4(3) - (-3)(5) = 27

e(5,3)   5(3) - 3(1) = 12

f(1,3)     1(6) - 3(-2) = 12

a(-2,6)

each of the cross products is twice the area of the triangle with the associated side and one vertex the origin. so the area of abo=26/2=13.

area = (1/2) (26 + 19 +   18 + 27 + 12 + 12) = 57

that checks!