7. axb=a+a+a+etc. to 6 times = 6 times a or ba. - 63 + 25x - 194 - [3y - {4x - (5y - 62)}] - 65 + 25x – 194 – 3y + 4x - 5y +63 = 29x – 27y. 8. See Mansford, page 14 {a-(6-c+d)} {a-b-(-d)} = {(a-6)+(c-d)} {(a - b)-(c-d)} =(a - b) - (-2)2 (al - 2ab +62) - (2-2cd+d) ea - 2ab + 62 - + 3cd - aa. If a = 4, b= 3, C= 2, d=1, the last result = 16 - 24+9 - 4+4-1 = 29 – 29 = 0. 9. 3(a - b)+2(c-a) – 4{6+21c-a)} = 32 – 35 + 20 - 21 – 46 – 80+ 8a 9a - 76-6c. 2ac + 362 – 26c + 308 =3(a2 +62 +62) – 2(ab + ac + bc). 10. See Mansford's Algebra, also previous answers in this series. If x= 1, y = -2, 3- 3. у % + 3 I 2 12 + sz: 1. 6 24 24 12 11. (x + 4)2 + (x - 4)2 + (x + 6)2 + (x - 6)2 – 3(x+8) (x - 8) (x+4)= 32+ 8x + 16 2 +104 + 296 4.72 I 12. 1 – 2x - (1 - {1-(1 - 2x)} - (1 - 2x)] =I - 2x {1-1 -1 + 2x} - 1+2x] = 1 – 2x - (1 - 1+1 – 2x – 1+2x] = 1 - 2x, and (1 - 2x)% = 1 - 46+ 4x2 13. {(a + b)2 + (a - b)2} {(a+)2 – (a –0)2} = (a + b)* - (a - b)* GREATEST COMMON MEASURE. 1. -a2 as (* a-x - 23 Dividing this remainder by a’, we have x - a. *-a) (*+a a2 ax ax ..X-a, G. C. M. 2. G. C. M. of gax?y2 and 15a2xy = 3axy. ** - 4x + 3)37 - 2033 15x+2(3* 20x2 ( -8 - 8) – 8x2 + 6x +2 x2 - 4x ***-138 +12 12). + 3x3 + 12x -16(+3 3.48 + 13x2 – 16 12(*-3 3x3 + 3x2 - 4x4 - 3x2 9x + 12 9x + 12 .. G. C. M. = x2 + 3x - 4. If x = 1, both expressions will vanish. I-13+ 12 = 0, 1+3+ 12 – 16=0. с |