Ejercicio 10

78.7a -9b +6a -4b = +13a -13b

7a +6a = +13a

-9b -4b = -13b

79. A +b –c –b –c +2c –a = 0

a –a = 0

+b –b = 0

-c +2c –c = 0

80. 5x -11y -9 +20x -1 –y = 25x -10 -12y

5x +20x = 25x

-9 -1 = -10

-11y –y = -12y

81. -6m +8n +5 –m –n -6m -11 = -12m -7n – 7

-6m –m -6m = -12m

+8n –n = -7n

+5 -11 = -7

82. –a +b +2b -2c +3a +2c -3b = 2 a

-a +3a = 2 a

+b +2b -3b = 0

-2c +2c = 0

83. -81x +19x -30z +6y +80x +x -25y = -30z

-81x +80x +x = 0

+19y +6y -25y = 0

-30z = -30z

84. 15a2 -6ab -8a2 +20 -5ab -31 +a2 –ab = 8ª2 -12ab -11

15a2 -8a2 +a2 = 16 – 8 = 8a2

-6ab -5ab –ab = -12ab

+20 -31 = -11

85.-3a +4b -6a +81b +31a –a –b = +21a -30b

-3a -6a +31a –a = +21a

+4b +81b -114b –b = -30b

86. -71a3b-84a4b2+50a3b+84a4b2 -45a3b +18a3b = 48a3b

-71a3b +50a3b -45a3b -45a3b +18a3b = 48a3b

-84a4b2 + 84a4b2 = 0

87.–a+b –c +8 +2a +2b -19 -2c -3a -3 -3b+3c =-6a+6b-6c-30

-a +2a -3a = -6a

+b+2b -3b= +6b

-c -2c +3c = 6c

+8 -19 -3 = -30

88. m2 +71mn -14m2 -65mn +m3 –m2 -115m2 +6m3=

131m2 +136mn +9m3

m2 -14m2 –m2 -115m2 = 131m2

+71mn -65mn = +136mn

+m3 +6m3 = 9m3

89. x4y –x3y2 +x2y -8x4 –x2y – 10 +x3y2 -7x3y2 -9 +21x4y –y3 +50 = +30x4y -9x3y2 +70 +2y2y

X4y -8x4y +21x4y = +30x4y

-x3y2 +x3y2 -7x3y2 = -9x3y2

-10 -9 –y3 +50 = +70

+ x2y -x2y = +2x2y

90. 5ax+1 -3bx+2 -8cx+3 -5ax+1 -50 +4bx+2 -65 –bx+2 +90 +cx+3 +7cx+3 = 8bx+2 -205 +16cx+2

5ax+1 -5ax+1 = 0

-3bx+2 +4bx+2 –bx+2 = 8bx+2

+90 -50 -65 = -205

+8cx+3 +cx+3 +7cx+3 = +16cx+2

91. Am+2 –xm+3 -5 +8 -3am+2 +5xm+3 -6 +am +2 -5xm+3=

+5m+3 -11m+3 -9

Am+2 -3am+2 +am+2 = +5m+2

-xm+3 +5xm+3 -5xm+3 = -11m+3

-5 +8 -6 = -19

92. 0.3a +0.4b +0.5c -0.6a -0.7b -0.9c +3a -3b -3c =

2.7a -3.3b -3.4c

0.3a -0.6a +3a = +2.7a

+0.4b -0.7b -3b = -3.3b

+0.5c -0.9c -3c = -3.4c

93.3/5m2 -2mn +1/10m2 -1/3mn +2mn -2m2 = -m -0.3

3/5m2 +1/10m2 -2m2 = -m

-2mn -1/3mn +2mn = -0.3

94. -3/4a2 +1/2ab -5/6b2 +2 1/3a2 -3/4ab +1/6b2 -2ab =

-19/12ª2 -9/4ab –b2

-3/4a2 +2 1/3a2 = -19a2/12

+1/2ab -3/4ab -2ab = -9/4ab

-5/6b2 +1/6b2 = b2

95. 3/25am-1 -7/50b-2 +3/5am-1 -0.2am-1 +1/5bm-2 =

3/25am-1 +1/5m-2

3/25am-1 +3/5am-1 -0.2am-1 = 3/25am-1

-70/50b-2 +1/5bm-2 = +1/5m-2