Answer:
90° counterclockwise rotation
Plot the situation
The quadratic formula is ![\frac{-b+-\sqrt[2]{b^2-4ac}}{2a}](https://tex.z-dn.net/?f=%5Cfrac%7B-b%2B-%5Csqrt%5B2%5D%7Bb%5E2-4ac%7D%7D%7B2a%7D)
and in the equation ax^2+bx+c=0
so now all you have to do is substitute the numbers into the quadratic formula
Answer: A
Explanation: The zeroes of f(x) are the value/s of x such that f(x) = 0. So, we need to find the values of x in the equation f(x) = 0.
Note that
f(x) = 0
⇔ x² + 3x - 10 = 0
By factoring into binomials, x² + 3x - 10 = (x + 5)(x - 2). Thus,
x² + 3x - 10 = 0
⇔ (x + 5)(x - 2) = 0
⇔ x + 5 = 0 or x - 2 = 0
⇔ x = -5 or x = 2
Hence, the zeroes of x are -5 and 2.
When two lines cross like this, sum of measures of opposite angles is 180.
this means that:
measure angle AEC + measure angle BED = 180
4x-40 + x+50 = 180
5x +10 = 180
5x = 170
x = 34
therefore:
measure angle AEC = 4x-40 = 4(34)-40 = 96
measure angle BED = x+50 = 34+50 = 84
There are 10 seniors in the class, from which 4 should be chosen by the teacher. The order of the chosen students does not matter. This means that we speak of combinations. THe equation for calculating the number of possible combinations is:
C=N!/R!(N-R), where N is the total number of objects and R is the number of objects we select from the N
In our case, N=10, R=4.
C= 10!/4!*6!=10*9*8*7*6!/6!*4*3*2*1=<span>10*9*8*7/24=5040/24=210
There are 210 different ways for the teacher to choose 4 seniors in no particular order.</span>
