Find b and then solve the equation: 2x^2+bx−10=0, if one of its roots is 5

Mathematics

2 answers:

cestrela7 [59]3 years ago

5 0

Answer:

the b value is -8, i just had this problem in my hw, and the value is -8 because the value of c will be equal to -b x a; it seems the other guy forgot the negative.

Step-by-step explanation:

slavikrds [6]3 years ago

4 0

Vietas formula tells us that the product of our two roots is equal to the constant term of a quadratic over the leading coefficient, so:

[tex] r_1r_2=-\frac{-10}{2} \implies 5*r_1=-5 \implies r_1=-1[\tex]

It also tells us that the b term in our quadratic is equal to the negative of the sum of the terms divided by the leading coefficient, so:

[tex] r_1+r_2=-\frac{b}{2} \implies 4=-\frac{b}{2} \implies b=-8 [\tex]

So, one of our roots is 5, the other is -1, and our b value is 8.

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A family reunion will include a picnic. Hamburger buns come in packages of 8 and the hamburger patties come in packages of 20. H

IrinaVladis [17]

Answer:

Step-by-step explanation:

20+8= 28

5 0

3 years ago

70 POINTS!

siniylev [52]

You can solve this question with pythagorean theorem > ${a}^{2} + {b}^{2} = c^{2}$

Based on the information, you already have one side (a or b, doesn't matter, 12) and the hypotenuse (the cut, c, 15)

So:
1. $12^{2} + b^{2} = 15^{2}$
2. 144+ $b^{2}$ = 225
3. $b^{2}$ = 225 - 144 = 81
4. $b= \sqrt{81}$
5. $b=9$

7 0

3 years ago

I need help with 6 & 8

zimovet [89]

1. We need to get rid of those pesky parentheses. We do this by distributing the 3.

2. We need to get "n" by itself, so we add 9 to both sides.

3. Add like terms.

4. Now, we need to get rid of the -9, so we divide both sides by -9. Remember that dividing by negative numbers changes the direction of the "greater than or equal to" symbol.

5. We divide, and the negatives cancel.

I wrote the answer both ways so that I could tell what the number line needed to look like.