Question

What are the solutions of the quadratic equation (x + 3)(x +3) = 49? Ax = -2 and x = -16 Bx = 2 and x = -10 Cx = 4 and x = -10 Dx = 40 and x = -58

Answer 1

4 and -10

Explanation:

`\displaystyle (x + 3)(x +3) = 49 \\ x^2+3x+3x+9=49 \\ x^2 +6x+9=49 \\ x^2 + 6x + 9 - 49 = 0 \\x^2+6x-40=0 \\\\ \Delta=b^2-4ac \\ \Delta=6^2-4 \cdot 1 \cdot (-40) \\ \Delta=36+160 \\ \Delta=196 \\ \\ X_(1,2)=(-b \pm √(\Delta) )/(2a)  \\ \\ X_1=(-b+√(\Delta) )/(2a) = (-6+14)/(2) = (8)/(2)=4 \\ \\ X_2=(-b-√(\Delta) )/(2a)  = (-6-14)/(2)=(-20)/(2) = -10`