а) X² -144=0б)100-81x²=0в)196-y²=0г)225y² -64=0

X² -144=0
X²=144>0
X $_{1}$ =√144=12
X $_{2}$ =-√`44=-12

100-81x²=0
-81x²=-100
x²= $\frac{100}{81}$ >0
x $_{1}$ = $\sqrt{ \frac{100}{81} }$ = $\frac{10}{9} = 1 \frac{1}{9}$
x $_{2}$ = $- \sqrt{ \frac{100}{81} } =- \frac{10}{9} =-1 \frac{1}{9}$

196-y²=0
-y²=-196
y²=196>0
y $_{1}$ =√196=14
y $_{2}$ =-√196=-14

225y² -64=0
225y²=64
y²= $\frac{64}{225}$ >0
y $_{1}$ = $\sqrt{ \frac{64}{225} } = \frac{8}{15}$
y $_{2}$ = $- \sqrt{ \frac{64}{225} } = -\frac{8}{15}$