Question

porfavor ajudaaaaaaaa ;-;​

Answer 1

Explicação passo a passo:

12)

${AB\over BC}={ED\over CD}\\ \\ {AB\over4,5}={2\over1,8}\\ \\ 1,8.AB=2.(4,5)\\ \\ 1,8.AB=9\\ \\ AB={9\over1,8}\\ \\ AB=5$

A distância entre as duas margens é 5m

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13)

${x\over4}={y\over10}~~\to x+y=21\\ \\ {x+y\over4+10}={21\over14}={3\over2}\\ \\ \\ {x\over4}={3\over2}\\ \\ 2x=12\\ \\ x={12\over2}\\ \\ \boxed{x=6m}\\ \\ \\ {y\over10}={3\over2}\\ \\ 2y=30\\ \\ y={30\over2}\\ \\\boxed{ y=15m}$