Help NO SPAM I will give brainliest if you get it correct, and show your work. √(5x+21)=x+3

Step-by-step explanation:

5x + 21 = x² + 2*x*3 + 3²

5x + 21 = x² +6x + 9

x² + 6x+9 -5x - 21 = 0

x² + 6x - 5x +  9 -21 = 0

x² + x - 12 = 0

Sum = 1

Product = -12

Factors = 4 , -3    {4*(-3) = -12  and 4 + (-3) = 1}

x² + 4x - 3x - 12 = 0

x(x + 4) - 3(x +4) = 0

(x + 4)(x - 3) =0

x = - 4 , 3

Step-by-step explanation:

Equation Given:

Solution:-

Square both sides and remove square root:

Subtract x^2+6x+9 from both sides :

Factor LHS of the equation:

Put factors = to 0:

Let's check.

First x=3 :

Put the values on the given Equation According to the question to verify:

(True)

Hence, this equation is true when x = 3.

Now x=-4:

Put the values on the given Equation According to the question to verify:

(False)

The equation is false when x = -4 is plugged, so the actual answer will be x = 3 where the equation comes true after putting the values.

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I hope this helps!

ghjmutmum

step-by-step explanation: