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3 years ago

What does x equal in 3x + 5 = -7

Mathematics

1 answer:

Stolb23 [73]3 years ago

6 0

Answer:-4

Step-by-step explanation:

Subtract 5 from each side, which leaves you with 3x=-12. Then divide each side by 3. Then that leaves you with x=-4

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if α and β are the zeroes of the polynomial 3x^2 - 8x − 3 then find the value of i) α^2 + β^2 ii) α^-1 + β^-1

BlackZzzverrR [31]

Step-by-step explanation:

the answer is in the above image

5 0

2 years ago

What is the sum of 20x^2-10x-30

ivann1987 [24]

Answer:

The sum of the roots is 0.5

Step-by-step explanation:

The correct question is

What is the sum of the roots of 20x^2-10x-30

we know that

In a quadratic equation of the form

$ax^{2} +bx+c=0$

The sum of the roots is equal to

$-\frac{b} {a}$

in this problem we have

$20x^{2} -10x-30=0$

$a=20\\b=-10\\c=-30$

substitute

$-\frac{(-10)} {20}=0.5$

Verify

Find the roots of the quadratic equation

The formula to solve a quadratic equation is equal to

$x=\frac{-b\pm\sqrt{b^{2}-4ac}} {2a}$

$a=20\\b=-10\\c=-30$

substitute

$x=\frac{-(-10)\pm\sqrt{-10^{2}-4(20)(-30)}} {2(20)}$

$x=\frac{10\pm\sqrt{2,500}} {40}$

$x=\frac{10\pm50} {40}$

$x=\frac{10+50} {40}=1.5$

$x=\frac{10-50} {40}=-1$

The roots are x=-1 and x=1.5

The sum of the roots are

$-1+1.5=0.5$ ----> is ok

5 0

3 years ago

The cost of a school banquet is 75$ plus 15$ per person.

ivann1987 [24]

Answer:

The cost of a school banquet is $75+30n, where n is the number of people attending.

If 53 people are attending to visit school banquet, then you have to find the value of given expression at n=53.

At n=53, the value is $(75+30·53)=$1,665.

Step-by-step explanation:

4 0

3 years ago

Whats the squareroot of 18

andreev551 [17]

Answer:

it should be 4.24264068712 looked it up

4 0

3 years ago

Read 2 more answers

Help me graph y=3-|x-1|

nexus9112 [7]

Answer:

In the photo below.

6 0

3 years ago