Question

Calcule a raiz ou solução das seguintes equações, sendo $U = Q$

a) 12x - 10 = 5x + 11 e) 10 - 4x = 9 - 2x
b) 7x + 5 = 68 - 2x f) 3x + 9 = 12
c) 14 - 3x = 2x + 19 g) 3y + 5 = 12 - y
d) 8x - 9 = 2x + 11 h) 8m - 16 = 6m - 10

Answer 1

Resposta:

$a)12x-10=5x+11\\\\12x-10+10=0\\\\12x=5x+11+10\\\\12x=5x+21\\\\12x-5x=21-5x\\\\7x=21\\\\x =21:7\\\\x=3$

$b)7x+5=68-2x\\\\7x+5-5=0\\\\7x=68-2x-5\\\\7x=-2x+63\\\\7x+2x=63+2x\\\\9x=63\\\\x=63:9\\\\x=7$

$c) 14-3x=2x+19\\\\14-3x-14=2x+19-14\\\\-3x=2x+5\\\\-3x-2x=5-2x\\\\-5x=5\\\\x =5:-5\\\\x=-1$

$d)8x-9=2x+11\\\\8x-9+9=0\\\\8x=2x+11+9\\\\8x=2x+20\\\\8x-2x=11+9\\\\6x=20\\\\x=20:6\\\\x=\frac{10}{3}$

$e)10-4x=9-2x\\\\10-4x-10=9-2x-10\\\\-4x=-2x-1\\\\-4x+2x=-1+2x\\\\-2x=-1\\\\x=-1:-2\\\\x=\frac{1}{2}$

$f)3x+9=12\\\\3x+9-9=0\\\\3x=12-9\\\\3x=3\\\\x=3:3\\\\x=1$

$g)3y+5=12-y\\\\3y+5-5=0\\\\3y=12-y-5\\\\3y=-y+7\\\\3y+y=7+y\\\\4y=7\\\\y=7:4\\\\y=\frac{7}{4}$

$h)8m-16=6m-10\\\\8m-16+16=0\\\\8m=6m-10+16\\\\8m=6m+6\\\\8m-6m=6-6m\\\\2m=6\\\\m=6:2\\\\m=3$