3x squared + 10x - 8 = 0.

Solve by completing the square.

3x^2+10x-8=0

a=3. b=10. c=-8
a*b
3*-8= -24 (now you need to find two factors of -24 when added you get b which is 10.)
-2*12= -24
-2+12= 10
So -2 and 12 is the two factors, now remove 10 and use them, don’t worry remember those factors when added equal 10
(3x^2+12x)-(2x-8)=0
3x(x+4)-2(x+4)=0. (When multiplying, dividing, adding or subtracting two negative it become a positive so that’s how -2 into -8 I got +4)
(x+4) (3x-2)
X+4=0. 3x-2=0
X= -4. 3x= 2
3x/3 = 2/3
x=2/3

I hope this helps you!!