Let's simplify step-by-step.
2/
5
y−4+7−
9
/10
y
=
2
/5
y+−4+7+
−9
/10
y
Combine Like Terms: =
2
/5
y+−4+7+
−9
/10
y
(2
/5
y+
−9
/10
y)+(−4+7)
=
−1
/2
y+3
Answer: =
−1
/2
y+3
Hope I could help! :)
2. Dividing exponential expression with the same base is what the left hand fractional expression is. Z^8/Z^?=z^6. Since all the bases are the same. To get the exponential power 6 on the right we subtract the denominator’s (bottom part of the fraction) exponential power (on the left) from the numerator’s (top part) exponential power.
Then, 8 - ? = 6? 2 is the only number to make the left equal the right side. This, z^8/z^2=z^6
Tbh I really don’t know and I hope someone helps you