Solve the System Of Equations (any variable works) 4x + 6y - z = -18
3x + 2y - 4z = -24
-5x + 3y + 2z = 15

Step-by-step explanation:

8x + 12y - 2z = -36

-5x + 3y + 2z= 15

3x + 15y = -21

3x + 2y - 4z = -24

-10x + 6y + 4z = 30

-7x + 8y = 6

3x + 15y = -21

-21x + 24y = 18

 21x + 105y = -147

129y = -129

y = -1

3x - 15 = -21

3x = -6

x = -2

-8  - 6 - z = -18

-14 - z = -18

-z = -4

z = 4

x = -2, y = -1, z = 4

b.) 160 miles on a 5 gallons car

step-by-step explanation:

240/10=24 miles/gallon

160/5=32 miles/gallon

30/1=30 miles/gallon

168/6= 28 miles/gallon

32 miles/gallon is the most amount, so this is the best.

14

step-by-step explanation:

14 x 3 = 42