I’ll mark you brainliest

42

Step-by-step explanation:

In a rectangle, the diagonals have the same length. Therefore:

Hope this helps!

BD = 42

x=12 is found below as a way to find x

We can find 42 by adding together the equations

3x+6 = 5x-18

+18 = 5x(-3x-6)

18 + 6 = 2x

24 = 2x

x= 12  

We can then plug in for 5x and 3x

as BD = 5x-18 = 3x+6

5(12) = 60 -18 = 42 and 3(12) =36+6 = 42

To find line BD = 42

Step-by-step explanation:

3x+6= 42

3x = 42-6

3x = 36

x = 12

5x-18 = 60

5x = 60- 18

5x = 42

x=12

what i would say the best answer is a. 40.5

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116