Answer: 16y² - x²
Step-by-step explanation: The - sign means a difference, so the choices with + signs are eliminated (though 64x² and 9 are squares)
10 is not a square so that one is eliminated (though the y² and the 4x² are squares)
16 is the square of 4, y² is the square of y, and x² is the square. That expression shows a difference of squares.
1 electron has a mass of 9.1 X 10-31 kg. How many electrons n does it take to make 1 kg?
(1 e)/(9.1 X 10-31 kg) = n/(1 kg)
So, n = 1.10 X 1030 electrons
Each electron has a charge of 1.6 X 10-19 C, where C stands for Coulombs. So, the n electrons have a charge of q = ne = (1.10 X 1030 electrons) X (1.6 X 10-19 C/electron) = 1.76 X 1011 C.
Answer:
b and c
Step-by-step explanation:
both slopes are 2/3
#22. We are given that y = 1/4. So, we want to plug this value into the expression 15/y:
15/(1/4)
When you divide by a fraction, you should follow the rule “flip the guy and multiply”. Basically, 15/(1/4) = 15 * 4 = 60.
The answer for #22 is (D).
#23. We can use a proportion:
(The shaded area)/(entire circle area) = (360 - 60)/360
But, we don’t have to find the areas of the region and circle; we can just solve the fraction:
(360 - 60)/360 = 300/360 = 30/36 = 5/6
The answer for #23 is (A).
