49. Let x be A's money in £s; then B has 491 − x; and C has 381 − x; .. 491-x+381-x=52; 8x=140; .. x=17}: .. A has £17. 10s.; B has £31. 15s.; C has £21. 54. then and x=240-3x; .. x=60. Let x be the number of panes in each window of upper row; x+4 x+6 middle row; lowest row; 18x=108; .. x=6: .. 6x+6(x+4)+6(x+6)=168; . 6, 10, 12 are the numbers. 55. Let x be the number of hours for the first part; (N.B. This produces a quadratic equation; the question is changed in the 5th edition.) 58 (As in Edition V. 1886). Let x be the sum of money, in shillings; hence B's score was 20, and A's 11; i.e. A was beaten by 9. 7. From (1), from (2), substitute in (1); then 8. From (1), from (2), substitute in (1); then' 9. From (1), from (2), substitute in (1); then 10. From (1), from (2), substitute in (1); then 11. From (1), from (2), substitute in (1); then 12. From (1), from (2), substitute in (1); then 13. From (1), from (2), substitute in (1); then 14. From (1), from (2), substitute in (2); then 15. From (1), from (2), substitute in (1); then 6x+10y=74; 6x+9y=69; .. y=5: 3x+25=37; .. 3x=12; or x=4. 12x+15y=129;. ́. 12x+8y=80; .. 7y=49; .. y=7: 4x+35=43; .. 4x=8, or x=2. 14x+4y=142; 14x+49y=7; .. -45y=135; .. y=-3: 7x-6=71; .. x=11. 28x-35y=0; 28x+24y=236; -59y=-236; .. y=4: 4x-20=0; .. x=5. 55x-22y=275; 16x-22y=2; .. 39x=273; .'. x=7: 35-2y=25; .. y=5. 30x-15y=225; 21x-15y=45; .. 9x=180; .. x=20: 120-3y=45; .. y=25. 20x+6y=164; 63x+6y=465; .. -43x=-301; ... x=7: |