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3 years ago

Solve x2+x-1=0 using the quadratic formula.

Mathematics

1 answer:

weeeeeb [17]3 years ago

6 0

Answer:

x = $\frac{-1 ±\sqrt{5} }{2}$

Step-by-step explanation:

Ignore the A that doesn't belong in the answer

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Twice the sum of a number and six decreased by fifteen is the same as eighteen more than the product of five and the number. Fin

Arlecino [84]

Answer:

-9

Step-by-step explanation:

2(n+6) -15 = 5n+18

2n + 12 - 15 = 5n + 18

2n - 3 = 5n + 18

2n = 5n + 21

-3n = 21

n = -9

4 0

3 years ago

Merle Fonda opened a new savings account. She deposited $40,000 at 10% compounded semiannually. At the start of the fourth year,

IrinaVladis [17]

Use compound interest formula F=P(1+i)^n twice, one for each deposit and sum the two results.

For the P=$40,000 deposit,
i=10%/2=5% (semi-annual)
number of periods (6 months), n = 6*2 = 12
Future value (at end of year 6),
F = P(1+i)^n = 40,000(1+0.05)^12 = $71834.253

For the P=20000, deposited at the START of the fourth year, which is the same as the end of the third year.
i=5% (semi-annual
n=2*(6-3), n = 6
Future value (at end of year 6)
F=P(1+i)^n = 20000(1+0.05)^6 = 26801.913

Total amount after 6 years
= 71834.253 + 26801.913
=98636.17 (to the nearest cent.)

8 0

3 years ago

Given that (ax^2 + bx + 3) (x + d) = x^3 + 6x^2 + 11x + 12<br> a + 2b - d = ?

Mariulka [41]

Answer:

Let's solve for a.

(ax2+bx+3)(x+d)=x3+6x2+11x+12a+2b−d

Step 1: Add -12a to both sides.

adx2+ax3+bdx+bx2+3d+3x+−12a=x3+6x2+12a+2b−d+11x+−12a

adx2+ax3+bdx+bx2−12a+3d+3x=x3+6x2+2b−d+11x

Step 2: Add -bdx to both sides.

adx2+ax3+bdx+bx2−12a+3d+3x+−bdx=x3+6x2+2b−d+11x+−bdx

adx2+ax3+bx2−12a+3d+3x=−bdx+x3+6x2+2b−d+11x

Step 3: Add -bx^2 to both sides.

adx2+ax3+bx2−12a+3d+3x+−bx2=−bdx+x3+6x2+2b−d+11x+−bx2

adx2+ax3−12a+3d+3x=−bdx−bx2+x3+6x2+2b−d+11x

Step 4: Add -3d to both sides.

adx2+ax3−12a+3d+3x+−3d=−bdx−bx2+x3+6x2+2b−d+11x+−3d

adx2+ax3−12a+3x=−bdx−bx2+x3+6x2+2b−4d+11x

Step 5: Add -3x to both sides.

adx2+ax3−12a+3x+−3x=−bdx−bx2+x3+6x2+2b−4d+11x+−3x

adx2+ax3−12a=−bdx−bx2+x3+6x2+2b−4d+8x

Step 6: Factor out variable a.

a(dx2+x3−12)=−bdx−bx2+x3+6x2+2b−4d+8x

Step 7: Divide both sides by dx^2+x^3-12.

a(dx2+x3−12)

dx2+x3−12

−bdx−bx2+x3+6x2+2b−4d+8x

dx2+x3−12

−bdx−bx2+x3+6x2+2b−4d+8x

dx2+x3−12

Answer:

−bdx−bx2+x3+6x2+2b−4d+8x/

dx2+x3−12

Step-by-step explanation:

8 0

3 years ago

Can anyone check this if it’s right.

Romashka [77]

Yes this is the right answer

6 0

3 years ago

I'm doing math homework and the boy next to me asked what the mean to there numbers is, 22, 26, 28, 30, 39, 44, 62, and 63 what

AfilCa [17]

22+26+28+30+39+44+62+63= 314 Divide the answer by the amount of numbers =39.25

8 0

3 years ago

Read 2 more answers