The teacher will be very surprised to see your correct solution 😉
1 20
84 = 7/10*4200*3/10*--*log(2)*60 - -- - 20
21 x
a1 = 1
b1 = 1/(104 - 2520*log(2))
a2 = 1
b2 = -x/20
-x/20 = 1/104+1/2520*log+1/2)
x = 1/(104 - 2520*log(2)) / (-1/20)
5
x_1 = --------------------
2*(-13 + 315*log(2))
sum
5 -------------------- 2*(-13 + 315*log(2))
=
5 -------------------- 2*(-13 + 315*log(2))
product
5 -------------------- 2*(-13 + 315*log(2))
=
5 -------------------- 2*(-13 + 315*log(2))