Use the quadratic formula to solve the equation.

3x^2 + 10x + 7 = 0

By ax² + bx + c = 0 form..

a = 3
b = 10
c = 7

So by quad. formula...

x = (-b ± √(b² - 4ac))/2a
= (-10 ± √(10² - 4*3*7))/(2*3)
= (-10 ± √(100 - 84))/6
= (-10 ± √16)/6
= (-10 ± 4)/6
= (-10 + 4)/6 and (-10 - 4)/6
= -6/6 and -14/6
= {-1,-7/3}

I hope this helps!