<span>(-30,15 : 15 + 0,91) * (-2,4) = (-2,01 +0,91 ) *(-2,4) = -1,1 *(-2,4) =2,64</span>
1) (x-7)²-7²=0
(x-7-7)(x-7+7)=0
(x-14)*x=0
x1= 0, x2= 14
2) 10²-(z-19)²=0
(10-z+19)(10+z-19)=0
(29-z)(z-9)=0
z1= 9, z2= 29
3) (6+y)²-9²=0
(6+y-9)(6+y+9)=0
(y-3)(y+15)=0
y1= 3, y2= -15
4) 5²-(13+t)²=0
(5-13-t)*(5+13+t)=0
(-8-t)(t+18)=0
t1= -8, t2= -18
по формулам приведения: