Question

Solve the quadratic equations for the values of x...

Answer 1

x(x+1)=12

3*4 = 12 so x1 = 3

-4*(-3) = 12 xo x2 = -4

or

x² + x - 12 = 0
(x-3)(x+4) = 0, hence x1 = 3 or x2 = -4

or by the formula

x1 , x2 = (-b +/- sqrt(b² - 4ac))/2a

x1 = (-1 + sqrt(1 - (-4*1*12))/2
= (-1 + sqrt(49))/2
= 6/2 = 3

x2 = (-1 - sqrt(1 + (-4*1*12))/2
= (-1 - sqrt(49))/2
= -8/2 = -4

Answer 2

so in the book it says -4,3 is the answer

Answer 3

there are two answers for which the equation is true
for x =- 4
and when x = 3

if you substitute them in the original equation, you'll xee it is true
Like so,
3² + 3 = 12, so that is ok
and also
(-4)² -4 = 12

Answer 4

ok thank you :)

Answer 5

So, it is possible to solve this in 3 possible ways. I hope you see that