Question

resolva as equacoes em R. a) 8x-9=3x+21 b) 4(x+2)=2(x+4)+8 c) xsobre2+xsobre4=9sobre1

Answer 1

a)
8x-9 = 3x+21
8x-3x = 21+9
5x = 30
x = 6

b)
4(x+2)=2(x+4)+8
4x+8 = 2x+8+8
4x-2x = 16-8
2x = 8
x = 4

c) 
$\frac{x}{2} + \frac{x}{4} = 9\\\\ \frac{2x+x}{4} = 9\\\\ 3x = 9.4\\\\ 3x = 36\\\\ x = 12$