2y^2-7y+6=0 7x^2-34x-5=0 5y^2+3y=0 x^2-2x-3=0 7c^2+13c-2 решить уравнения и найти корни,

1) 2y² -7y +6 =0
D =49 -4×2×6=1
x1 =(7 -1)/4 =6/4=1.5
x2 =(7+1)/4 =2
ответ: x =1.5; x =2

2) 7x² -34x -5 =0
D =34² +4×7×5=1296=36²
x1 =(34 -36)/14 = -2/14 = -1/7
x2 =(34 +36)/14 =5
ответ: x = -1/7; x =5

3) 5y² +3y =0
y(5y +3)=0
y =0
5y +3=0
y = -3/5 = -0.6

4) x² -2x -3 =0
D =4 +4*3 =16 =4²
x1 =(2 -4)/2 = -1
x2 =(2+4)/2=3

5) 7c² +13c -2 =0
D =13² +4*7*2 =225 =15²
x1 =(-13 -15)/14 = -2
x2 =(-13 +15)/14 =2/14 =1/7