Three times x is less then -6 and greater then -21

-21 < 3x < -6

OR -6 > 3x > -21

Step-by-step explanation:

Take a part each section of the word form. Translate each section into algebraic form (numbers and symbols) and put the sections back together.

"Three times x": 3x        A number and variable together multiply

"is less than -6": < -6

"and greater than -21": > -21

When writing that a number is > or <, you can also write the number on the other side, change the symbol, and it will mean the same thing.

< -6 is the same as -6 >

> -21  is the same as -21 <

The number remains on the same open or closed side of the symbol.

The problem tells use that "3x" is between -21 and -6. Put the sections back together, but write 3x in the middle.

-21 < 3x < -6

You can also write:

-6 > 3x > -21

You can write them either way, but some teachers prefer smaller number to bigger number from left to right.

d. $180

step-by-step explanation:

if the dimensions of the room is 9ft by 12 ft, we have the area of the floor as,

so the area of the floor is 108 square feet, converting that into square yards we get,

the cost of carpet is $15 per square yard, therefore the cost of carpet for 12 square yards is,

hence, the cost of carpet is $180.

assuming the dimensions of the room be,

15 ft by 12 ft

so, the area of the floor of that room is,

we can convert 180 square feet into square yards, we know that,

1 sq ft = 0.111 sq yard

so, 180 square feet is,

so the area of floor is 20 square yards.

now, the cost of carpet is 15 dollars per square yard, therefore the cost of carpet for 20 square yards is,

so, it will cost $300.