The distributive property states that a(b+c)=ab+ac.
In this situation, 4(x+2)= 4*x+ 4*2.
While the student multiplied 4*2 to get 8, the student did not multiply 4*x to get 4x.
Order of operations is one way
I=PRT
I=interst
P=invested amount
R=rate in decimal
T=time in years
given
P=680
R=3.5%=0.035
T=6
I=680*0.035*6
I=142.8
that is interest
total is interest+principal=680+142.8=822.8
after 6 years, $822.80 is in the account
