1)x^2-49=0
X^2=49
√x^2=√49
|x|=7
X¹=7 x²=-7
2)16x^2+25=0
X^2=-25/16
√X^2=√-25/16
|x|=5/4
X1=5/4 x2=-5/4
(3x-5)^2-16=0
9x^2-30x+25-16=0
9x^2-30x+9=0|:3
3x^2-10x+3=0
D=b^2-4ac=100-36=64
X1=-b+√d/2a=10+8/6=3
X2=10-8/6=1/3
100\%+20\%=120\%=1,2