This is a simple equation:
x - 7 < 14
x < 14 + 7
x < 21
→ Many people think that because there is not "=" sign they don't flip the sign of what in this case is -7. But actually, the symbols "<" and ">" act as the equal sign. This rule doesn't apply to positive number, only negative.
Hope it helped,
BioTeacher101
(If you have any questions, feel free to ask them in the comments)
Answer: A
Step-by-step explanation:
Answer:
72$
Step-by-step explanation
How to insert in a calculator 90-20%= 72
How to take 20% from a price
Divide the original price by 5. <em>18</em>
Subtract this new number from the original one. <em>90 - 18 </em>
The number you calculated is the discounted value. <em>90 - 18 = </em><u><em>72</em></u>
Answer:
<em>Cathy was born in 1980 and she was 18 years old in 1998</em>
Step-by-step explanation:
<u>Equations</u>
This is a special type of equations where all the unknowns must be integers and limited to a range [0,9] because they are the digits of a number.
Let's say Cathy was born in the year x formed by the ordered digits abcd. A number expressed by its digits can be calculated as

In 1998, Cathy's age was

And it must be equal to the sum of the four digits

Rearranging

We are sure a=1, b=9 because Cathy's age is limited to having been born in the same century and millennium. Thus

Operating

If now we try some values for c we notice there is only one possible valid combination, since c and d must be integers in the range [0,9]
c=8, d=0
Thus, Cathy was born in 1980 and she was 18 years old in 1998. Note that 1+9+8+0=18
Answer:
dont u have the answer
Step-by-step explanation: