Question

Resolva as equações de 1 grau com duas incógnitas caso 4:
a) 2x – y = 46, y = 26
b) 3x – y = 54, y = 36
c) 4x – y = 120, y = 40
d) 5x – y = 65 , y = 55
e) 2x – y = 78, y = 28
f ) 3x – y = 72, y = 66

Answer 1

Resposta:

$a:\ x=36\\\\b:\ x=30\\\\c:\ x=40\\\\d:\ x=24\\\\e:\ x=53\\\\f:\ x=46$

Explicação passo a passo:

$a)\ 2x-y=46,\ y=26\\\\2x-26=46\\2x=46+26\\2x=72\\x=\frac{72}{2}\\x=36\\\\\\b)\ 3x-y=54,\ y=36\\\\3x-36=54\\3x=54+36\\3x=90\\x=\frac{90}{3}\\x=30\\\\\\c)\ 4x-y=120,\ y=40\\\\4x-40=120\\4x=120+40\\4x=160\\x=\frac{160}{4}\\x=40$

$d)\ 5x-y=65,\ y=55\\\\5x-55=65\\5x=65+55\\5x=120\\x=\frac{120}{5}\\x=24\\\\\\e)\ 2x-y=78,\ y=28\\\\2x-28=78\\2x=78+28\\2x=106\\x=\frac{106}{2}\\x=53\\\\\\f)\ 3x-y=72,\ y=66\\\\3x-66=72\\3x=72+66\\3x=138\\x=\frac{138}{3}\\x=46$