Chris has 4 rocks that each weigh 12 kilograms. He keeps them in a box that weighs 6 kilograms. He can lift all of the rocks in the box above his head at once. Estimate how many kilograms Chris can lift above his head.

45

Step-by-step explanation:

my brain told me

54

Step-by-step explanation:

if each rock weighs 12 kilo and there are 4, you multiply 4 and 12. Then you add the other six that he lifted above his head that is the box. You should get 54

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

idk

step-by-step explanation: