Answer:
Step-by-step explanation:
I'm not sure my way is going to be any quicker or better. Let's take an example.
Suppose you start with 456
Put a decimal at the end of the 6. You get 456.
Shift the decimal to the left one place 45.6
Divide by 2
22.8 (done mentally)
Note: dividing by 2 is easier than dividing by 5. Or multiplying by 5 for that matter.
Check the result.
456 * 5/100 =2280 / 100.
Shift a decimal 2 places to the left.
22.80 which agrees with your result.
Answer:
outliar is23
Step-by-step explanation:
A) I would make the positive integer x and then form an equation.
x + 30 = x^2 - 12
x + 42 = x^2
0 = x^2 - x - 42 this can be factorised
(x - 7) ( x + 6) Therefore x = 7 or x = -6
Since the question asks for a positive integer the answer is 7.
B) two positive numbers x and y.
X - y = 3
x^2 + y^2 = 117
Use these simultaneous equations to figure out each number.
Rearrange the first equation
x = y + 3
Then substitute it into the second equation.
(y+3)^2 + y^2 = 117
y^2 + 6y + 9 + y^2 = 117
2y^2 + 6y - 108 = 0
then factorise this.
(2y - 12) (y + 9)
This means that y = 6 or y = -9 but it’s 6 because that’s the only positive number.
Use y to find x
x = y + 3
x = 6 + 3
x = 9
So the answers are x = 9 and y = 6.
I believe Hector is correct
Explanation: for every 1 hour the income is $10, therefore working 32 hours will give you $320 as Hector stated, while working 18 hours will not give you $160 as Hannah stated, it will give you $180
