Can someone plz answer number 10 and 11 don’t worry about number 12

9514 1404 393

  10.  x = 4

  11.  x = -5

Step-by-step explanation:

10. Use the perimeter formula. Collect terms, subtract* the constant, divide by the coefficient of the variable.

  P = 2(L+W)

  42 = 2(5x +(x-3))

  21 = 6x -3 . . . . . . divide by 2, collect terms

  24 = 6x . . . . . . . . add 3

  4 = x . . . . . . . . . .  divide by 6

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11. Collect terms, subtract the constant, divide by the coefficient of the variable.

  -8x -3(2x +1) = 67

  -8x -6x -3 = 67 . . eliminate parentheses

  -14x -3 = 67 . . . . . collect terms

  -14x = 70 . . . . . . . add 3

  x = -5 . . . . . . . . . . divide by -14

* "Subtract" and "add the opposite" are the same mathematical operation. In both these problems, the constant we want to get rid of is -3, so we add 3 (the opposite of -3). Of course, that operation is done to both sides of the equation.

b

step-by-step explanation:

the word superfluous means unnecessary