Question

determine o valor de x nas proporção a seguir

d)3x/21 = 5/7


e)2x-1/x+2 = 3/5

f)x-5/3 = x-1/4​

Answer 1

Resposta:

$d)\\ \\ {3x\over21}={5\over7}\\ \\ 21x=5(21)\\ 21x=105\\ x=105\div21\\ \\ x=5\\ \\ e)\\ {2x-1\over x+2}={3\over5}\\ \\ 5(2x-1)=3(x+2)\\ 10x-5=3x+6\\ 10x-3x=6+5\\ 7x=11\\ \\ x={11\over7}\\ \\ f)\\ {x-5\over3}={x-1\over4}\\ \\ 4(x-5)=3(x-1)\\ 4x-20=3x-3\\ 4x-3x=-3+20\\ \\ x=17$