Question

Me ajudem é pra entregar hoje

Answer 1

$1-a)\\\\\begin{bmatrix}x+2b=y-2\\ x=7\\ b=3\end{bmatrix}\\\\\begin{bmatrix}x=7\\ x+2\cdot \:3=y-2\end{bmatrix}\\\\\begin{bmatrix}x=7\\ x+6=y-2\end{bmatrix}\\\\\begin{bmatrix}7+6=y-2\end{bmatrix}\\\\\begin{bmatrix}13=y-2\end{bmatrix}\\\\x=7,\:b=3,\:y=15$

$1-b)\\\\\begin{bmatrix}a+2a=4a-x\\ a=12\end{bmatrix}\\\\\begin{bmatrix}12+2\cdot \:12=4\cdot \:12-x\end{bmatrix}\\\\\begin{bmatrix}36=48-x\end{bmatrix}\\\\x=12,\:a=12$

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2 -

17/25 = 0.68 ou seja 68%

2/5 = 0.4 ou seja 40%

23/50 = 0.46 ou seja 46%

5/2 = 2.5 ou seja 250%

8/20 = 0.4 ou seja 40%