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.
Answer:
Step-by-step explanation:
1/2 (6x-10) - x
Opening bracket
= 6x/2 - 10/2 - x
= 3x - 5 - x
= 2x - 5
Answer:
The answer is C=942.48
Step-by-step explanation:
You would figure this out by using the formula C=2πr.
So let's break this down.
Circumference (C) equals (=) pi (π) times 2 times the radius of the circle.
Since the problem gave you the diameter which is the length from one side of the circle to the other, you have to divide the diameter in half. Which would give you a radius of 150.
Taking the 150 you would multiply 10*2*π.
Which would give you....(drumrollllll)
C=942.48
I hope this helps!!
p.s. have any more questions? Post them and comment the link!♥, Sadie
Answer:
A : 25
Step-by-step explanation:
In a neutral atom, the number of electrons is equal to the number of protons. The atomic number indicates the number of protons.
The mass number is the sum of the number of neutrons and the number of protons.
mass number=protons+neutrons
As we know from the atomic number, the number of neutrons is 14 and the number of electrons is 11.
mass number = 14 + 11
