Write an equation for the description The length of a rectangle is twice its width. The perimeter of the rectangle is 131 feet.
=

Step-by-step explanation:

A) l = 2 * w

B) 131 = 2l + 2w

B) 2l = 131 -2w

B) l = 65.5 -w

Substituting this into A)

65.5 -w = 2w

3w = 65.5

width = 21.8333333333

length = 43.6666666666

Double - Check

131 = 2 * 21.833333333 + 2 * 43.6666666666

131  = 43.6666666  + 87.33333333

131 = 131

Step-by-step explanation:

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places