jwb no 19 smpe 23 ya no ,n pke cara ..thx guys ☺

19.B.SR
20.x²= 15²- (5+4)²
=225 - 9²
=225-81
x=√144
=12

21.x²=25²-(18-3)²
=625-15²
=625-225
x =√400
=20
22.r=p²-d²-r
=25²-20²-10
=625-400-10
=√225
=15-10
=5
23.x²=12²+(7-2)²
=114+5²
=144+25
x =√169
=13