Answer:
[tex]ET=34\ units[/tex]
Step-by-step explanation:
see the attached figure to better understand the problem
we know that
The diagonals of a rectangle are equal and bisect each other.
so
ET=RC
and
[tex]2x-3=x+7[/tex]
Solve for x
[tex]2x-x=7+3[/tex]
[tex]x=10[/tex]
Find the measure of diagonal RC
[tex]RC=(2x-3)+(x+7)[/tex]
[tex]RC=(3x+4)[/tex]
substitute the value of x
[tex]RC=3(10)+4[/tex]
[tex]RC=34\ units[/tex]
Remember that
ET=RC
therefore
[tex]ET=34\ units[/tex]