3x²+x-5=0
a = 3, b = 1, c= -5
-> ∆ ( delta ) = b²-4ac = 61 > 0
-> x1 =( -b+√∆ )÷ 2a =...
x2 = (-b-√∆)÷2a =...
p/s: do your teachers teach you how to use ∆ ( delta ) in maths calculation ? i live in europe and our teachers teach us that way. however, it is a rịght and fast way. you should learn it.