1. x² = 16 ; x=±√16=±4
2. t²=81 ; t=±√81=±9
3. r²-100=0 ; r²=100 ; r=±√100=±10
4. x²-144=0 ; x²=144 ; x=±√144=±12
5. 2s²=50 ; s²=25 ; s=±√25=±5
6. 4x²-225=0; 4x²=225; x²=225/4 ; x=±√(225/4)=±15/2
7. 3h²-147=0; 3h²=147; h²=147/3=49; h=±√49=±7
8. (x-4)²=169; x-4=±√169=±13;
When x-4 = 13, x=17
" x-4 = -13, x=-9
9. (k+7)²=289; k+7=±√289=±17;
When k+7 = 17, k=10
" k+7 = -17, k=-24
10. (2s-1)²=225; 2s-1=±√225=±15
When 2s-1=15, s=8
" 2s-1=-15, s=-7
