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2 years ago

Solve x2 - 10x = -21

Mathematics

2 answers:

ipn [44]2 years ago

8 0

Answer:

add 21 to both sides to get everything on one side

x^2 - 10x + 21 = 0

do factorization, guess and check

(x - 7) (x -3) = 0

x =7, and x =3

Mariana [72]2 years ago

4 0

Answer:

x= 7,3

Step-by-step explanation:

Move all terms to the left side and set equal to 0. Then set each factor = to 0

Hope this helps please make me brainliest!

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NEED HELP!!!!<br><br> Please

AnnZ [28]

Answer:

# 1,3 and 6

Step-by-step explanation:

4 0

2 years ago

What are the coordinates of a point that is 7 strides west of (2,-1)

Marat540 [252]

(-5,-1) would be the coordinates since the only thing we’re changing by moving west is that we’re subtracting from the x value. Therefore, 2-7 is -5 so we get -5,-1

4 0

2 years ago

Joey and Armando live on the same st as the park. The park is 9/10 mile from Joey's home. Joey leaves home and walks to Armando'

AleksandrR [38]

Let's start by assuming Armando's house is between Joey's and the park.

Let $x$ be the distance Joey walked to Armando's house.

<span>The park is 9/10 mile from Joey's home. Joey leaves home and walks to Armando's home. Then Joey and Armando walk 3/5 mile to the park.

</span> $\dfrac{9}{10} = x + \dfrac{3}{5}$

$x = \dfrac{9}{10} - \dfrac{3}{5} = \dfrac{9}{10} -\dfrac{6}{10} = \dfrac{3}{10}$

That's probably the answer they're looking for. But what if the park is between Joey and Armando's houses or Joey is between the park and Armando? (The latter isn't really possible with the given distances.)

Let $a, b, c$ be the distances between three collinear points like we have here. Our equation is really a few equations in one, something like

$\pm a \pm b = \pm c$

Let's get rid of the plus/minuses. Squaring,

$a^2 + b^2\pm 2ab = c^2$

$\pm 2ab = c^2-a^2-b^2$

$4a^2b^2 = (c^2-a^2-b^2)^2$

For us, that's a quadratic equation for $c^2$

$4(9/10)^2(3/5)^2= (c^2-(9/10)^2 - (3/5)^2)^2$

I'll skip right to the solutions,

$c^2=\dfrac{9}{100} \textrm{ or } c^2=\dfrac{9}{4}$

$c=\dfrac{3}{10} \textrm{ or } c=\dfrac{3}{2}$

We could have gotten the 3/2 just by adding 9/10+3/5 but this was more fun.

6 0

3 years ago

The total weight of 25 bags of rice, 23 bags of flour and 19 bags of sugar is 2,719 pounds. Each bag of rice weighs 35 pounds an

Tems11 [23]

Just do 25 23 then what

4 0

2 years ago

What is the sum of the numbers in the series? 15 + 11 + 7 + . . . + (–129)

babymother [125]

Using Gauss's method
Total number of terms = [15-(-129)]/4+1=36+1=37
Add
S=15+11+7+....-125-129
S=-129-125-...+7+11+15
--------------------------------
2S=-114-114-114...(37 times)
=>
sum=S=(1/2)*(-114)*37=-2109

Using AP, T(n)=15+11+7+....-129
T(n)=19-4n => T(1)=15, T(37)=-129
S(n)=(1/2)(37)(T(1)+T(37)=(1/2)37(15-129)=2109

3 0

2 years ago