Answer:
[tex] x = -7 \pm \sqrt{10 [/tex]
Step-by-step explanation:
The x-intercepts occur where y = 0.
-3/5(x + 7)² + 6 = 0
-3(x + 7)² + 30 = 0
-3(x² + 14x + 49) + 30 = 0
-3x² - 42x - 147 + 30 = 0
3x² + 42x + 117 = 0
[tex] x = \dfrac{-42 \pm \sqrt{42^2 - 4(3)(117)}}{2(3)} [/tex]
[tex] x = \dfrac{-42 \pm \sqrt{360}}{6} [/tex]
[tex] x = \dfrac{-42 \pm 6\sqrt{10}}{6} [/tex]
[tex] x = -7 \pm \sqrt{10 [/tex]
