What are the solutions of 3x2 + 15 = −6x

x = -1 + 2 i or x = -1 - 2 i

Step-by-step explanation:

Solve for x:

3 (x^2 + 5) = -6 x

Expand out terms of the left hand side:

3 x^2 + 15 = -6 x

Add 6 x to both sides:

3 x^2 + 6 x + 15 = 0

Divide both sides by 3:

x^2 + 2 x + 5 = 0

Subtract 5 from both sides:

x^2 + 2 x = -5

Add 1 to both sides:

x^2 + 2 x + 1 = -4

Write the left hand side as a square:

(x + 1)^2 = -4

Take the square root of both sides:

x + 1 = 2 i or x + 1 = -2 i

Subtract 1 from both sides:

x = -1 + 2 i or x + 1 = -2 i

Subtract 1 from both sides:

x = -1 + 2 i or x = -1 - 2 i

Step-by-step explanation:

the 2 figures are congruent bc if you reflect abcd over the y axis then over the d axis the figures overlap