Solve using the quadratic formula: (2x+1) (x-3)= -7?

Question

what is the answer

Answer 1

x = (5 - i√7) / 4 and x= (5 + i√7) / 4

Using the quadratic formula like you requested....

(2x+1)(x-3) = -7

2x² -6x + x - 3 = -7

2x² -5x +4 = 0

[ -(-5) ± (√-5² - 4(2)(4)) ] / 2(2)

[5 ± (√25-32)] /4

[5 ± (√-7)] / 4

[5 ± (√-1)(√7) ] / 4

(5 ± i√7) / 4 (Remember √-1 = i )

x = (5 + i√7) / 4 and x = (5 - i√7) / 4

Answer 2

(2x+1)(x-3) = -7

2x^2 - 6x + x - 3 + 7 = 0

2x^2 - 5x + 4 = 0

divide by 2

x^2 - (5/2)x + 2 = 0

complete the square

x^2 - 2(5/4)x + 25/16 - 25/16 + 2 = 0

(x - 5/4)^2 +7/16 = 0

(x - 5/4)^2 = -7/16

x - 5/4 = sqrt(-7/16)^2

x - 5/4 = ± (1/4)sqrt(7)i

x = 5/4 ± (1/4)sqrt(7)i

x =(1/4)[ 5 + sqrt(7)i] or (1/4)[5 - sqrt(7)i]

Answer 3

3x2 – 7x + 3 =0 a million. First multiply the coefficient of x^2 with the consistent(3). 2. Then get 2 components of the ensuing term so as that their sum is the coefficient of the middle term(-7). 3. Then replace the middle term coefficient of the above equation with those components and you gets 4 words extremely of three. 4. Distribute those into 2 communities. 5. Take problem-loose ingredient from each and each team and then finally from the words which provide you the factorization of the given espression. 6. placed each and each ingredient =0 and you gets the fee of x.

Answer 4

(2x+1)(x-3) = -7
2x^2 +x-6x-6 = -7
2x^2-5x+1 = 0
Then use quadratic formula to find x
b = -5
b^2-4ac = 25-16 = 9
x1= (5+sqt(9)) / 4 = 2
x2 = (5-sqt(9)) /4 = 1/2

Answer 5

x=-4

Answer 6

2 x ² - 5 x - 3 = - 7
2 x ² - 5 x + 4 = 0
x = [ 5 ± √(25 - 32) ] / 4
x = [ 5 ± i √ 7 ] / 4

Answer 7

(2x+1)(x-3)=(2x^2-6x+x-3)=-7
2x^2-5x+4=0
This equation is of form ax^2+bx+c
a = 2 b = -5 c = 4
x=[-b+/-sqrt(b^2-4ac)]/2a]
x=[5 +/-sqrt(-5^2-4(2)(4)]/(2)(2)
discriminant is b^2-4ac=-7
Discriminant < 0 : No real roots

Answer 8

(2x+1) (x-3)= -7
2x^2+x-6x-3=-7
2x^2-5x-3+7=0
2x^2-5x+4=0

a=2, b=-5 & c=4
x=[-b+-(sqrt{b^2-4ac})]/[2a]
x=[-{-5}+-(sqrt{(-5)^2-(4*2*4)})]/[2*2]
x=[5+-(sqrt{(25)-(32)})]/[4]
x=[5+-(sqrt{25-32})]/[4]
x=[5+-(sqrt{-7})]/[4]
x=[5+-(i2.646)]/[4]

or
2x+1=-7
2x=-7-1
2x=-8
x=-4

&
x-3=-7
x=-7+3
x=-4

Answer 9

just use FOIL and make it equal to 0
and use the formula