All categories

3 years ago

Find the discriminant: * 7x2 – 5 = 2x + 9x2

Mathematics

1 answer:

Fed [463]3 years ago

6 0

Answer:

-36

Step-by-step explanation:

You have to rearrange the quadratic into an equation where one side is zero.

This example works by subtracting 7x^2 from both sides leaving

-5 = 9x^2 - 7x^2 + 2x

-5 = 2x^2 + 2x

Now add 5 to both sides

-5 + 5 = 2x^2 + 2x + 5

0 = 2x^2 + 2x + 5

Now the equation you gave is in the form of a quadratic. The discriminate is found from

a = 2

b = 2

c = 5

b^2 - 4ac is the discriminate

2^2 - 4(2)(5)

4 - 40

Discrimate = 4 - 40 = - 36

You might be interested in

PLEASE HELP IMPORTANT MATH

VladimirAG [237]

A and C are the correct answers

5 0

4 years ago

PLSSSSSSS HELPPPPPPPP ASAPPPP

Ivanshal [37]

Answer:

Answer should be choice 4

Step-by-step explanation:

4 0

3 years ago

Find <img src="https://tex.z-dn.net/?f=a_%7B1%7D" id="TexFormula1" title="a_{1}" alt="a_{1}" align="absmiddle" class="latex-form

yKpoI14uk [10]

Answer:

$\displaystyle a_{1} = 108$

Step-by-step explanation:

we are given

the sum,common difference and nth term of a geometric sequence

we want to figure out the first term

recall geometric sequence

$\displaystyle S_{ \text{n}} = \frac{ a_{1}(1 - {r}^{n} )}{1 - r}$

we are given that

$S_n=189$
$r=\dfrac{1}{2}$
$n=3$

thus substitute:

$\displaystyle 189= \frac{ a_{1}(1 - {( \frac{1}{2} )}^{3} )}{1 - \frac{1}{2} }$

to figure out $a_1$ we need to figure out the equation

simplify denominator:

$\displaystyle \frac{ a_{1}(1 - {( \frac{1}{2} )}^{3} )}{ \dfrac{1}{2} } = 189$

simplify square:

$\displaystyle \frac{ a_{1}(1 - {( \frac{1}{8} )}^{} )}{ \dfrac{1}{2} } = 189$

simplify substraction:

$\displaystyle \frac{ a_{1} (\frac{7}{8} )}{ \frac{1}{2} } = 189$

simplify complex fraction:

$\displaystyle a_{1} (\frac{7}{8} ) \div { \frac{1}{2} } = 189$

calculate reciprocal:

$\displaystyle a_{1} \frac{7}{8} \times 2 = 189$

reduce fraction:

$\displaystyle a_{1} \frac{7}{4} \ = 189$

multiply both sides by 4/7:

$\displaystyle a_{1} \frac{7}{4} \times \frac{4}{7} \ = 189 \times \frac{4}{7}$

reduce fraction:

$\displaystyle a_{1} = 27\times 4$

simplify multiplication:

$\displaystyle a_{1} = 108$

hence,

$\displaystyle a_{1} = 108$

4 0

3 years ago

30 people go for dinner it costs £240.93 how much should each person pay

yKpoI14uk [10]

The answer is 8.031 per person

5 0

4 years ago

Find the surface area of polyhedra <br>Pls!! show how you got the surface area

quester [9]

Answer:

52.48

Step-by-step explanation:

find the cross sectional area which is the triangle

triangle = 1/2 x 8.2 x 6.4 = 26.24

then, use the area to multiply by the extended length of 2

26.24 x 2 = 52.48

4 0

3 years ago