Answer:
42
Step-by-step explanation:
It's just saying that 1/2 * x = 70, and if we multiply both sides by 2, we get
x=140.
we check if that number is true by finding 80% of 140.
4/5 * 140 = 112. So that means 140 is the number we want
30% of 140 is 3/10 * 140, which is 420/10, which is 42