What are the roots of 4x2 + 35x − 9 = 0?

Please help!! What Find the Error and explain why it is wrong!

Nata [24]

Answer:

First image attached

The error was done in Step E, because student did not multiply $2\cdot x -8$ by the negative sign in numerator. Step E must be $\frac{2\cdot x -5}{(x+4)\cdot (x-4)}$ .

Second image attached

The error was done in Step C, because the student omitted the $2\cdot a \cdot b$ of the algebraic identity $(a+b)^{2} = a^{2}+2\cdot a\cdot b +b^{2}$ . Step C must be $5\cdot x = x^{2}+4\cdot x + 4$

Step-by-step explanation:

First image attached

The error was done in Step E, because student did not multiply $2\cdot x -8$ by the negative sign in numerator. The real numerator in Step E should be:

$3-(2\cdot x -8)= 3-2\cdot x+8 = 11-2\cdot x$

Hence, Step E must be $\frac{2\cdot x -5}{(x+4)\cdot (x-4)}$ .

Second image attached

The error was done in Step C, because the student omitted the $2\cdot a \cdot b$ of the algebraic identity $(a+b)^{2} = a^{2}+2\cdot a\cdot b +b^{2}$ . Step C must be $5\cdot x = x^{2}+4\cdot x + 4$

And further steps are described below:

Step D

$x^{2}-x+4 = 0$

Which according to the Quadratic Formula, represents a polynomial with complex roots. That is: ( $a = 1$ , $b = -1$ , $c = 4$ )

$D = b^{2}-4\cdot a\cdot c$

$D = (-1)-4\cdot (1)\cdot (4)$

$D = -17$ (Conjugated complex roots)

Step E

$(x-0.5-i\,1.936)\cdot (x-0.5+i\,1.936) = 0$

Step F

$x = 0.5+i\,1.936\,\lor\,x = 0.5-i\,1.936$

8 0

2 years ago

100 points help with recursive function!

Allushta [10]

Answer:

a. 20.25

Step-by-step explanation:

6 0

1 year ago

Danielle has $3 in quarters and $2 in dimes in her pocket. If she randomly selects one coin out of her

sattari [20]

The answer is C. 3/5

6 0

2 years ago

Can someone tell me if these answers are right or not? These problems are getting on my nerves!

Bond [772]

1a. 3^1 / 3^2 = 3^1-2 = 3^-1 = 1/3^1 = 1/3.
2b. 4^2 / 4^4 = 4^2-4 = 4^-2 = 1/4^2.
3c. 6^3/6^5 = 6^3-5 = 6^-2 = 1/6^2.
4d. 3^-5 • 3^2 = 3^-10 = 1/3^10.

I believe for the last question its asking only to rewrite exponent as a positive exponent similar to the first question.

6 0

2 years ago

The expression 1.01 ⋅ 1.00 5 t 1.01⋅1.005 t 1, point, 01, dot, 1, point, 005, start superscript, t, end superscript gives the am

Nadya [2.5K]

Answer:

Step-by-step explanation:

The expression 1.01-1.005 gives the amount of money, in thousands of dollars, in Carter's savings account t years after he opens it What does 1.01 represent in this expression? Choose 1 answer Carter opened the savings account I year ago ⓢ Carter's savings account had $1,010 in it when he opened it. The amount of money in Carter's savings account increase by 1% each year.

1.01 ( 1.005 )^t

standard exponential equation is

y = a (b)^x

where a = initial value

comparing the two equations

we get

a = 1.01

so, it means 1.01 means Carters saving account had $ 1010 in it when it opened

6 0

2 years ago