Are you sure this is written correctly? Any number whose digits add to 9 is divisible by 9. For a 2 digit number then, your choices are
18, 27, 36, 45, 54, 63, 72, and 81. None of these has the property that for the 2 digit number AB that B=2A-1. Solving your question algebraically is possible but you get fractional digits.
Answer:
$0.80/oz
Step-by-step explanation:
$4 for 5 ounces
unit cost = price/weight = $4/(5 oz.) = $0.80/oz
The quadratic formula is above.
You want each equation in standard form: ax^2 + bx + c = 0
I begin each problem by defining variables.
For instance 3. Is in standard form. X^2 -2x - 3 = 0. a = 1, b = -2, c = -3
Now use quadratic formula: x = [- b + or - sqrt(b^2 - 4ac)]\2a
In the first number, 2 is in the thousand's place, it means two thousand.
in the second number, 2 is in the hundred's place. It means two hundred.
Answer: y=x+2
Step-by-step explanation: