Alright, lets get started.
The ages of all four sisters will be = x, x+2, x+4, x+6
As per given in question, two times of youngest sister age exceeds the oldest sister age by 30 means

Simplifying the equation



So this is the age of youngest sister.
So, age of oldest sister will be 
Hene the age of oldest sister is 42 years. : Answer
Hope it will help :)
Answer:
It might be 110 as the answer
The correct rectangular equivalence of 3sqrt(2)·cis(7pi/4 ) is:
3sqrt(2)·cos( 7pi/4 ) + i·sqrt(2)·sin( 7pi/4 ) = 3 - 3i.
<h3>Where did David go wrong?</h3>
David mistakenly interchanged the Sin function and the Cos function when he was calculating the problem.
Hence the correct rectangular equivalence is:
3sqrt(2)·cos( 7pi/4 ) + i·sqrt(2)·sin( 7pi/4 ) = 3 - 3i.
<h3>What is rectangular equivalence?</h3>
An equation is rectangular in form when it is comprised of Variables like X and Y and can be represented on a Cartesian Plane.
Learn more about rectangular equivalence at:
brainly.com/question/27813225
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