You could subtract 4.53x from 7.21x and have 2.68x+1.12
Answer: a) k >4.08
b) k = 4.08
c) k<4.08
Step-by-step explanation:
Since we have given that

a) For what values of k will the function have no zeros?
It mean it has no real zeroes i.e. Discriminant < 0
As we know that

Here, a =-3
b = 7
c = -k
So, it becomes,

b) For what values of k will the function have one zero?
It means it has one real root i.e equal roots.
So, in this case, D = 0
So, it becomes,

c) For what values of k will the function have two zeros?
It means it has two real roots.
In this case, D>0
So, it becomes,

Hence, a) k >4.08
b) k = 4.08
c) k<4.08
Step-by-step explanation:
-2x - 5y = 16___(1)
2x - 3y = -16___(2)
(1) + (2) ==> -2x -5y = 16
(+) <u>2x -3y = -16</u>
-8y = 0
y = 0/-8
y = 0
y=0 in (1)
(1)---> -2x-5y =16
-2x - 5(0) = 16
-2x - 0 = 16
-2x = 16
x = 16/-2
x = -8
x = -8 , y = 0
-5x + 2y = 11__(1) ; -3x + 4y = -13___(2)
multiply eqn(1) with 2
2 × (1) : -10x + 4y = 22___(3)
(3) - (2) :. -10x + 4y = 22
(-) <u>-3x </u><u>+</u><u> </u><u>4</u><u>y</u><u> </u><u>=</u><u> </u><u>-</u><u>1</u><u>3</u>
-7x = 35
x = 35/-7
x = -5
x=-5 in (1)
(1) : -5x + 2y = 11
-5(-5) + 2y = 11
25 + 2y = 11
2y = 11 - 25
2y = -14
y = -14/2
y = -7
x = -5 , y = -7
Using the mean concept, it is found that we will need 15 more points to bring up his average up to 90%.
The mean of a data-set is the <u>sum of all observations divided by the number of observations</u>.
In this problem:
- In the first 5 observations, total of 21 out of 25 points, hence the mean for these observations is
. - In the next n observations, mean of 1.
Hence, the mean is:

We want the mean to be of 0.9, thus:





3 more testes are need, each worth 5 points, hence, 15 more points are needed to bring up his average up to 90%.
A similar problem is given at brainly.com/question/25323941