Answer:
1. -21
2. 0
3.

Explanation:
1. 18 =

multiply both sides by the reciprocal of -6/7.
18 =


-21 = h
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2.

find the LCM of both fractions.
LCM = 8
multiply both fractions by the LCM

-6x = 21x
subtract 21x from both sides
-6x-21x = 21x-21x
-27x = 0
isolate x
-27x/-27 = 0
x = 0
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3.

multiply both sides by the reciprocal of -1/2.

z =

hope this helps :)