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4 years ago

Solving Quadratic Equations- Factorable 2x^2 - 7x -15= 0

Mathematics

1 answer:

Pepsi [2]4 years ago

6 0

Step-by-step explanation:

$2{x}^{2} - 7x - 15 = 0$

can be factored to

$(2x + 3)(x - 5) = 0$

Hence,

$x = 5$

$x = - \frac{3}{2}$

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I NEED HELP NOW!!! Help pls ASAP

kkurt [141]

Answer:

linear

Step-by-step explanation:

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3 years ago

A quadratic equation is shown below: 3x2 − 15x + 20 = 0 Part A: Describe the solution(s) to the equation by just determining the

Triss [41]

Answer:

$\text{The roots of }3x^2+5x-8=0\text{ are }x=1,\frac{-8}{3}$

Step-by-step explanation:

$\text{Part A: Given a quadratic equation }3x^2-15x+20=0$

$\text{Comparing above equation with }ax^2+bx+c=0$

a=3, b=-15, c=20

Discriminant can be calculated as

$D=b^2-4ac$

$D=(-15)^2-4(3)(20)=225-240=-15$

The roots are imaginary

The solution is

$x=\frac{-b\pm\sqrt{D}}{2a}$

$x=\frac{-(-15)\pm \sqrt{-15}}{2(3)}=\frac{15\pm\sqrt{15}i}{6}$

The roots are not real i.e these are imaginary

$\text{Part B: Given a quadratic equation }3x^2+5x-8=0$

$\text{Comparing above equation with }ax^2+bx+c=0$

a=3, b=5, c=-8

Discriminant can be calculated as

$D=b^2-4ac$

$D=(5)^2-4(3)(-8)=25+96=121>0$

The roots are real

By quadratic formula method

The solution is

$x=\frac{-b\pm\sqrt{D}}{2a}$

$x=\frac{-5)\pm \sqrt{121}}{2(3)}=\frac{-5\pm 11}{6}$

$x=1,\frac{-8}{3}$

which are required roots.

I choose this method because I can get the solutions directly by substituting the values in formula, and I don't have to guess the possible solutions.

6 0

3 years ago

there are 480 students in a class. the ratio of boys to girls is 1:3. How many students are girls in the class?

vodka [1.7K]

Answer:360

Step-by-step explanation:

3+1=4

480 divided by 4= 120

120x1=120 so there are 120 boys

120x3=360 so there are 360 girls

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3 years ago

3 -1 ___ 1/4 which one is the correct answer. = < >

Likurg_2 [28]

3-1 = 2

2 is greater than 1/4

so > is the answer

7 0

3 years ago

Read 2 more answers

jada has already taken 4 pages of notes on her own, and she will take 2 pages out during each class session. In all, how many cl

stich3 [128]

Answer:

Step-by-step explanation:

I don't totally understand you question but if its 4 pages originally then she takes 2 pages every class, then

56-4= 52 (56 pages minus the 4 she already took).

52/2= 26 (52 pages divided by 2 pages per class)

4 0

3 years ago