Answer:
See below
Step-by-step explanation:

18cms because if I take 6cms times 3cms it will equal 18cms.
Answer: x= 1.9
Step-by-step explanation:
Answer: x = -30
Steps: 19 + x/2 = 4
Subtract 19 from both sides: 19 + x/2 - 19 = 4 - 19
Simplify: x/2 = 15
Multiply both sides by two: x/2 (2) = -15 (2)
Simplify: x = -30