One solution of 10x^2 + bx – 3 = 0 is - 4/5 find b and the other solution.
what is the value of b in the equation?

see explanation

Step-by-step explanation:

Given that x = - is a solution of the equation

Then substitute this value into the equation and solve for b

10 ( - )² + b(- ) - 3 = 0

10 × - b - 3 = 0

- b - 3 = 0

Multiply through by 5

32 - 4b - 15 = 0

17 - 4b = 0 ( subtract 17 from both sides )

- 4b = - 17 ( divide both sides by - 4 )

b = ← value of b

Given α and β are the roots of a quadratic equation, then

α + β = -

let α = - , then with a = 10 and b = b

- + β = - = -

β = - + =

Hence the other solution is x =

answer: c

because if you look at the chart you can see a pattern and compare it to the question he simplify out your

but i think the formula is f(x)=6x

the value of x is 9 ⇒ answer b

step-by-step explanation:

* we can solve this problem using cosine and sine rule

- in δ abc

∵ ab = 36 , bc = 28 , ac = 16

- lets find the measure of angle b using the cosine rule

∵ cos b = [ab² + bc² - ac²]/2(ab)(bc)

∴ cos b = [36² + 28² - 16²]/2(36)(28)

∴ cos b = 19/21

∴ m∠b = cos^-1(19/21) ≅ 25°

- lets find the measure of angle a using the sine rule

∵ sina/bc = sinb/ac = sinc/ab

∴ sina/28 = sin25°/16 ⇒ by using cross multiplication

∴ sina = 28 × sin25°/16

∴ sina = 0.7396

∴ m∠a = sin^-1(0.7396) ≅ 48°

- from the figure m∠abd = m∠dbc

∵ m∠abc = 25°

∴ m∠abd = 25°/2 = 12.5°

- in δabd

∵ m∠a = 48° , m∠abd = 12.5°

∵ the sum of the measures of the interior angles of any δ is 180°

∴ m∠adb = 180° - (48° + 12.5°) = 119.5°

∵ ab = 36

∵ ad = x

- use the sine rule to find x

∵ sin∠adb/ab = sin∠abd/x

∴ sin119.5°/36 = sin12.5°/x ⇒ by using cross multiplication

∴ x = 36 × sin12.5°/sin119.5° = 8.95 ≅ 9

* the value of x is 9