Answer:
66
Step-by-step explanation:
Use the formula for the mean of a set of numbers:
sum of the numbers
average = --------------------------------
count of numbers
Here we know that the average mark was 68, so we can write:
75 + 62 + 84 + 53 + x
average = 68 = ----------------------------------
5
or 274 + x
68 = -------------------
5
Solving for x, we multiply both sides by 5: 340 = 274 + x.
Subtracting 274 from both sides effectively isolates x:
340 = 274 + x
- 274 -274
------------------------
66 = x
The fifth student's mark was 66.
A graph of the equation shows the appropriate choice to be
C. 2_____
If you would rather, you can look at the value of the discriminant. For the equation y = ax²+bx+c, the discriminant (d) is
d = b²-4ac
For your equation, this evaluates to
d = (-8)²-4(2)(5) = 64 -40 =
24When the discriminant is
positive, the function has
two real roots (2 x-intercepts). When it is zero, there is only one x-intercept, and when it is negative, there are none (the roots are complex).
First you have to take the whole number (43) and then take the decimal and put it over 100 (77/100).
Answer:
A
Step-by-step explanation:
Given
x - 8 = - 12 ( multiply through by 3 to clear the fraction )
x - 24 = - 36 ( add 24 to both sides )
x = - 12 → A