Question

qual e o valor do x em cada caso
a) x_ - 4 = 20
8

b) x_ + 8 = 21
5
c) 7x_ - 3 = 11
4


me ajudem por favor por favor

Answer 1

$a)~~ \dfrac{x}{8} -4=20\to~~mmc=8\\\\ x-32=160\to\\\\ x=160+32\to\\\\ \boxed{x=192}$





$b)~~ \dfrac{x}{5} +8=21\to~~mmc=5\\\\ x+40=105\to\\\\x = 105 - 40 \to\\\\ \boxed{ x = 65}$





$c)~~ \dfrac{7x}{4} -3=11\to~~mmc=4\\\\ 7x-12=44\to\\\\7x = 44+12\to\\\\ 7x = 56\to\\\\ x= \dfrac{56}{7} \to\\\\ \boxed{x=8}$