Question

Find EF

Please and thanks

Answer 1

Given:

Given that CDEF is a rectangle.

The length of CD is 3x + 5

The length of EF is 7x - 39

We need to determine the length of EF.

Value of x:

We know the property that the opposite sides of a rectangle are congruent, then the two sides CD and EF are equal.

Thus, we have;

$CD=EF$

Substituting the values, we get;

$3x+5=7x-39$

       $5=4x-39$

     $44=4x$

     $11=x$

Thus, the value of x is 11.

Length of EF:

Substituting x = 11 in the length of EF, we get;

$EF=7(11)-39$

      $=77-39$

      $=38$

Thus, the length of EF is 38 units.

Answer 2

Answer:

38

Step-by-step explanation:

In a rectangle, opposite sides are equal

FE = CD

7x - 39 = 3x + 5

4x = 44

x = 11

EF = 7(11) - 39

38