Answer:
Addition.
Step-by-step explanation:
Multiplication is a faster way to do repeated addition.
For example, lets say you would add 10 fifteen's together. Addition would make it:
15 + 15 + 15 + 15 + 15 + 15 + 15 + 15 + 15 + 15
= 30 + 30 + 30 + 30 + 30
= 60 + 60 + 30
= 120 + 30
= 150
However, when multiplying:
15 x 10 = 150
As you can tell, multiplication makes it so there are less steps, and is less time consuming.
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Answer:
X=150
Step-by-step explanation:
4. C and D both are correct
12. H
11. B
Answer:
Radioactive in half life is 51gram
Step-by-step explanation:
80grams:12years
X :7.6years
12x÷x=x
7.6×80÷12=51gram
Answer:
50
Step-by-step explanation:
.3x=15
x=50