Respuesta :

Answer:

y= 8 and the diagonal = 32

Step-by-step explanation:

In a rectangle, both diagonals are equivalent. Using this information we set up the diagonal equations of AC and BD to each other, and then solve for y.

5y+12=7y+4

We have to isolate the variable, so we get the like terms on one side.

8=2y

8÷2=4

y=4

knowing that y =4 helps with each diagonal.

5(4)+12

20+12=32

7(4)+4

28+4=32