You know
Squaring both sides gives
Then raising both sides to any integer power 
gives
That is, any power of 
where the power is a multiple of 4 will always be equal to 1.
So
But perhaps you mean to write 20+1 as the exponent, in which case
'One third' as a decimal is 1 ÷ 3 = 0.333333..... ⇒ The decimal is recurring
'One fifth' as decimal is 1 ÷ 5 = 0.2 ⇒ The decimal terminates at the tenth value
'One seventh' as decimal 1 ÷ 7 = 0.142857142857.... ⇒ The decimal is recurring for every digit between 1 and 7
'One ninth' as decimal 1 ÷ 9 = 0.111111.... ⇒ The decimal is recurring
Answer: one fifth
Answer:
A money market account paying 3.5% interest, renewable for three-month commitments.
Your question answers itself. You solve by graphing.
I like to subtract one side of the equation from the other, so the solutions are where the graph crosses the x-axis (the resulting function value is zero).
It can be useful to find the "turning point" of each absolute value expression (where its value is zero) and graph that and some points on either side.
