Which equation shows the quadratic formula used correctly to solve 7x2 = 9 + x for x?

Quadratic formula for given equation is

Step-by-step explanation:

Given Quadratic Equation is  7x² = 9 + x

We need to find correct Quadratic formula for the given quadratic equation.

If the quadratic equation is in standard for,

ax² + bx + c = 0

then quadratic formula is given by,

First we rewrite the quadratic equation,

7x² - x - 9 = 0

by comparing with standard form of equation we get,

a = 7  ,   b = -1  and c = -9

oNw putting these value in quadratic formula we get,

Therefore, Quadratic formula for given equation is

answer: cos [   arcsin (3/5) - arccos (1/2) ] =

step-by-step explanation: × = 3/5 = 0.6--> x = 36.87 and x = 180 - 36.87 = 143.13 deg

cos y = 1/2 --> y = +- 60 deg a. cos (x - y) = cos (143.13 - 60) = cos 83,13  

=

0.12

b. cos (36.87 - 60) = cos (-23.23) = 0.92

since we know that the two functions are equal, f (x) = g

(x), therefore when we equate the two equations the result should be similar to

3x = x – 4:

a. f(x) = 3x, g(x) = x – 4

equating the two functions:

3x = x – 4             (correct)

so we now got our answer (a)