A digit is a number in one of the places, so for example the number 54 has two digits; a tens place digit (5) and a ones place digit (4).
Say the mystery number is a two digit number = xy
* that's not x times y but two side by side digits.
Info given:
<span>the sum of the digits of a two-digit number is 6
x + y = 6 </span>
<span>if the digits are reversed, yx the difference between the new number and the original number is 18.
**To obtain the number from digits you must multiply by the place and add the digits up. (Example: 54 = 10(5) + 1(4))
Original number = 10x + y
Reversed/New number = 10y + x
Difference:
10y + x - (10x + y) = 18
9y - 9x = 18
9(y - x) = 18
y - x = 18/9
y - x = 2
Now we have two equations in two variables
</span>y - x = 2
<span>x + y = 6
Re-write one in terms of one variable for substitution.
y = 2 + x
sub in to the other equation to combine them.
x + (2 + x) = 6
2x + 2 = 6
2x = 6 - 2
2x = 4
x = 2
That's the tens digit for the original number. Plug this value into either of the equations to obtain y, the ones digit.
2 + y = 6
y = 4
number "xy" = 24
</span>
I round the answer to the second digit and get 18.33
Answer:
f(-2) = -5
General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
<u>Algebra I</u>
Step-by-step explanation:
<u>Step 1: Define</u>
f(x) = 3x + 1
f(-2) is x = -2
<u>Step 2: Evaluate</u>
- Substitute in <em>x</em>: f(-2) = 3(-2) + 1
- Multiply: f(-2) = -6 + 1
- Add: f(-2) = -5
X=8
I believe that would be ur answer! I hope i helped out
B) D) and probably C) I’m not sure
