CAPITULO XXVIII
Problemas sobre ecuaciones simultaneas
Problemas sobre ecuaciones simultaneas
- Ejercicio 208
Elevar al cuadrado
- x 2 –2x+1 = ( [ x 2 –2x ] +1 ) 2 = ( x 2 –2x ) 2 +2( x 2 –2x ) +1 = x 4 –4 x 3 +4 x 2 +2 x 2 –4x+1 = x 4 –4 x 3 +6 x 2 –4x+1
- 2 x 2 +x+1 = ( [ 2 x 2 +x ] +1 ) 2 = ( 2 x 2 +x ) 2 +2( 2 x 2 +x ) +1 =4 x 4 +4 x 3 + x 2 +4 x 2 +2x+1 =4 x 4 +4 x 3 +5 x 2 +2x+1
- x 2 –5x+2 = ( [ x 2 –5x ] +2 ) 2 = ( x 2 –5x ) 2 +4( x 2 –5x ) + 2 2 = x 4 –10 x 3 +25 x 2 +4 x 2 –20x+4 = x 4 –10 x 3 +29 x 2 –20x+4
- x 3 –5 x 2 +6 = ( [ x 3 –5 x 2 ] +6 ) 2 = ( x 3 –5 x 2 ) 2 +12( x 3 –5 x 2 ) + 6 2 = x 6 –10 x 5 +25 x 4 +12 x 3 –60 x 2 +36
- 4 a 4 –3 a 2 +5 = ( [ 4 a 4 –3 a 2 ] +5 ) 2 = ( 4 a 4 –3 a 2 ) 2 +10( 4 a 4 –3 a 2 ) + 5 2 =16 a 8 –24 a 6 +9 a 4 +40 a 4 –30 a 2 +25 =16 a 8 –24 a 6 +49 a 4 –30 a 2 +25
- x+2y–z = ( [ x+2y ] –z ) 2 = ( x+2y ) 2 –2z( x+2y ) + z 2 = x 2 +4xy+4 y 2 –2xz–4yz+ z 2
- 3– x 3 – x 6 = ( [ 3– x 3 ] – x 6 ) 2 = ( 3– x 3 ) 2 –2 x 6 ( 3– x 3 ) + x 12 =9–6 x 3 + x 6 –6 x 6 +2 x 9 + x 12 =9–6 x 3 –5 x 6 +2 x 9 + x 12
- 5 x 4 –7 x 2 +3x = ( [ 5 x 4 –7 x 2 ] +3x ) 2 = ( 5 x 4 –7 x 2 ) 2 +6x( 5 x 4 –7 x 2 ) + ( 3x ) 2 =25 x 8 –70 x 6 +49 x 4 +30 x 5 –42 x 3 +9 x 2 =25 x 8 –70 x 6 +30 x 5 +49 x 4 –42 x 3 +9 x 2
- 2 a 2 +2ab–3 b 2 = ( [ 2 a 2 +2ab ] –3 b 2 ) 2 = ( 2 a 2 +2ab ) 2 –6 b 2 ( 2 a 2 +2ab ) + ( –3 b 2 ) 2 =4 a 4 +8 a 3 b+4 a 2 b 2 –12 a 2 b 2 –12a b 3 +9 b 4 =4 a 4 +8 a 3 b–8 a 2 b 2 –12a b 3 +9 b 4
- m 3 –2 m 2 n+2 n 4 = ( [ m 3 –2 m 2 n ] +2 n 4 ) 2 = ( m 3 –2 m 2 n ) 2 +4 n 4 ( m 3 –2 m 2 n ) + ( 2 n 4 ) 2 = m 6 –4 m 5 n+4 m 4 n 2 +4 m 3 n 4 –8 m 2 n 5 +4 n 8
- a 2 –b+ c 4 = ( [ a 2 –b ] + c 4 ) 2 = ( a 2 –b ) 2 + c 2 ( a 2 –b ) + ( c 4 ) 2 = a 2 4 –ab+ b 2 + ac 4 – bc 2 + c 2 16 = a 2 4 + b 2 + c 2 16 –ab+ ac 4 – bc 2
- x 5 –5y+ 5 3 = ( [ x 5 –5y ] + 5 3 ) 2 = ( x 5 –5y ) 2 + 10 3 ( x 5 –5y ) + ( 5 3 ) 2 = x 2 25 –2xy+25 y 2 + 2 3 x– 50 3 y+ 25 9
- 1 2 x 2 –x+ 2 3 = ( [ 1 2 x 2 –x ] + 2 3 ) 2 = ( 1 2 x 2 –x ) 2 + 4 3 ( 1 2 x 2 –x ) + ( 2 3 ) 2 = x 4 4 – x 3 + x 2 + 2 3 x 2 – 4 3 x+ 4 9 = x 4 4 – x 3 + 5 3 x 2 – 4 3 x+ 4 9
- a x – 1 3 + x a = ( [ a x – 1 3 ] + x a ) 2 = ( a x – 1 3 ) 2 + 2x a ( a x – 1 3 ) + ( x a ) 2 = a 2 x 2 – 2a 3x + 1 9 +2– 2x 3a + x 2 a 2 = a 2 x 2 – 2a 3x – 2x 3a + x 2 a 2 + 19 9
- 3 4 a 2 – 1 2 a+ 4 5 = ( [ 3 4 a 2 – 1 2 a ] + 4 5 ) 2 = ( 3 4 a 2 – 1 2 a ) 2 + 8 3 ( 3 4 a 2 – 1 2 a ) + ( 4 5 ) 2 = 9 16 a 4 – 3 4 a 3 + 1 4 a 2 +2 a 2 – 4 3 a+ 16 25 = 9 16 a 4 – 3 4 a 3 + 29 20 a 2 – 4 3 a+ 16 25
- a 2 4 – 3 5 + b 2 9 = ( [ a 2 4 – 3 5 ] + b 2 9 ) 2 = ( a 2 4 – 3 5 ) 2 + 2 b 2 9 ( a 2 4 – 3 5 ) + ( b 2 9 ) 2 = a 4 16 – 3 10 a 2 + 9 25 + a 2 b 2 18 – 2 b 2 15 + b 4 81 = a 4 16 – 3 10 a 2 + a 2 b 2 18 – 2 b 2 15 + b 4 81 + 9 25
- x 3 – x 2 +x+1 = ( [ x 3 – x 2 ] +[ x+1 ] ) 2 = ( x 3 – x 2 ) 2 +2( x 3 – x 2 ) ( x+1 ) + ( x+1 ) 2 = x 6 –2 x 5 + x 4 +2( x 4 + x 3 – x 3 – x 2 ) + x 2 +2x+1 = x 6 –2 x 5 + x 4 +2 x 4 –2 x 2 + x 2 +2x+1 = x 6 –2 x 5 +3 x 4 – x 2 +2x+1
- x 3 –3 x 2 –2x+2 = ( [ x 3 –3 x 2 ] –[ 2x–2 ] ) 2 = ( x 3 –3 x 2 ) 2 –2( x 3 –3 x 2 ) ( 2x–2 ) + ( 2x–2 ) 2 = x 6 –6 x 5 +9 x 4 –2( 2 x 4 –2 x 3 –6 x 3 +6 x 2 ) +4 x 2 –8x+4 = x 6 –6 x 5 +9 x 4 –4 x 4 +16 x 3 –12 x 2 +4 x 2 –8x+4 = x 6 –6 x 5 +5 x 4 +16 x 3 –8 x 2 –8x+4
- x 4 +3 x 2 –4x+5 = ( [ x 4 +3 x 2 ] –[ 4x–5 ] ) 2 = ( x 4 +3 x 2 ) 2 –2( x 4 +3 x 2 ) ( 4x–5 ) + ( 4x–5 ) 2 = x 8 +6 x 6 +9 x 4 –2( 4 x 5 –5 x 4 +12 x 3 –15 x 2 ) +16 x 2 –40x+25 = x 8 +6 x 6 +9 x 4 –8 x 5 +10 x 4 –24 x 3 +30 x 2 +16 x 2 –40x+25 = x 8 +6 x 6 –8 x 5 +19 x 4 –24 x 3 +46 x 2 –40x+25
- x 4 –4 x 3 +2x–3 = ( [ x 4 –4 x 3 ] +[ 2x–3 ] ) 2 = ( x 4 –4 x 3 ) 2 +2( x 4 –4 x 3 ) ( 2x–3 ) + ( 2x–3 ) 2 = x 8 –8 x 7 +16 x 6 +2( 2 x 5 –3 x 4 –8 x 4 +12 x 3 ) +4 x 2 –12x+9 = x 8 –8 x 7 +16 x 6 +4 x 5 –22 x 4 +24 x 3 +4 x 2 –12x+9
- 3–6a+ a 2 – a 3 = ( [ 3–6a ] +[ a 2 – a 3 ] ) 2 = ( 3–6a ) 2 +2( 3–6a ) ( a 2 – a 3 ) + ( a 2 – a 3 ) 2 =9–36a+36 a 2 +2( 3 a 2 –3 a 3 –6 a 3 +6 a 4 ) + a 4 –2 a 5 + a 6 =9–36a+36 a 2 +6 a 2 –18 a 3 +12 a 4 + a 4 –2 a 5 + a 6 =9–36a+42 a 2 –18 a 3 +13 a 4 –2 a 5 + a 6
- 1 2 x 3 – x 2 + 2 3 x+2 = ( [ 1 2 x 3 – x 2 ] +[ 2 3 x+2 ] ) 2 = ( 1 2 x 3 – x 2 ) 2 +2( 1 2 x 3 – x 2 ) ( 2 3 x+2 ) + ( 2 3 x+2 ) 2 = x 6 4 – x 5 + x 4 +2( 1 3 x 4 + x 3 – 2 3 x 3 –2 x 2 ) + 4 9 x 2 + 8 3 x+4 = x 6 4 – x 5 + x 4 + 2 3 x 4 + 2 3 x 3 –4 x 2 + 4 9 x 2 + 8 3 x+4 = x 6 4 – x 5 + 5 3 x 4 + 2 3 x 3 – 32 9 x 2 + 8 3 x+4
- 1 2 a 3 – 2 3 a 2 + 3 4 a– 1 2 = ( [ 1 2 a 3 – 2 3 a 2 ] +[ 3 4 a– 1 2 ] ) 2 = ( 1 2 a 3 – 2 3 a 2 ) 2 +2( 1 2 a 3 – 2 3 a 2 ) ( 3 4 a– 1 2 ) + ( 3 4 a– 1 2 ) 2 = a 6 4 – 2 a 5 3 + 4 a 4 9 +2( 3 a 4 8 – a 3 4 – a 3 2 + a 2 3 ) + 9 a 2 16 – 3a 4 + 1 4 = a 6 4 – 2 a 5 3 + 4 a 4 9 + 3 a 4 4 – 3 a 3 2 + 2 a 2 3 + 9 a 2 16 – 3a 4 + 1 4 = a 6 4 – 2 a 5 3 + 43 a 4 36 – 3 a 3 2 + 59 a 2 48 – 3a 4 + 1 4
- x 5 – x 4 + x 3 – x 2 +x–2 = ( [ x 5 – x 4 + x 3 ] –[ x 2 –x+2 ] ) 2 = ( x 5 – x 4 + x 3 ) 2 –2( x 5 – x 4 + x 3 ) ( x 2 –x+2 ) + ( x 2 –x+2 ) 2 = ( [ x 5 – x 4 ] + x 3 ) 2 –2( x 7 – x 6 +2 x 5 – x 6 + x 5 –2 x 4 + x 5 – x 4 +2 x 3 ) + ( [ x 2 –x ] +2 ) 2 = ( x 5 – x 4 ) 2 +2 x 3 ( x 5 – x 4 ) + x 6 –2( x 7 –2 x 6 +4 x 5 –3 x 4 +2 x 3 ) + ( x 2 –x ) 2 +4( x 2 –x ) + 2 2 = x 10 –2 x 9 + x 8 +2 x 8 –2 x 7 + x 6 –2 x 7 +4 x 6 –8 x 5 +6 x 4 –4 x 3 + x 4 –2 x 3 + x 2 +4 x 2 –4x+4 = x 10 –2 x 9 +3 x 8 –4 x 7 +5 x 6 –8 x 5 +7 x 4 –6 x 3 +5 x 2 –4x+4
