Answer:
x² + 8
Step-by-step explanation:
(f - g)(x)
= f(x) - g(x)
= 2x² + 1 - (x² - 7)
= 2x² + 1 - x² + 7 ← collect like terms
= x² + 8
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
<span> Compatible numbers are numbers that look nice or friendly with each other when we do mental calculation to estimate a product, but especially a division</span>
Small, because 1 divided by 8 = 0.125, and 3 divided by 4 = .75 Hope this helps!
Answer:
0.81
Step-by-step explanation: