Question

resolva as equações 
a) 5.(3-2a)=55
b)27=3.(x+3)
c)6.(4z+2)+7.(-5z+3)=66
d)16x + 2. (7x8)-9+67
e)12+(3x+6).(-7)-5=70

Answer 1

$a) \\ 5.(3-2a)=55 \\ \\ 15 - 10a = 55 \\ \\ -10a = 55 - 15 \\ \\ -10a = 40 (-1) \\ \\ 10a = -40 \\ \\ a = \dfrac{-40}{10} \\ \\ a = - 4$

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$b) \\ 27=3*(x+3) \\ \\ 27 = 3x + 9 \\ \\ -3x = 9 - 27 \ *(-1) \\ \\ 3x = -9 +27 \\ \\ 3x = 18 \\ \\ x = \dfrac{18}{3} \\ \\ x = 6$

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$c) \\ 6*(4z+2)+7*(-5z+3)=66 \\ \\ 24z + 12 - 35z + 21 = 66 \\ \\ 24z - 35z = 66 - 12 - 21 \\ \\ 11z = 33 \\ \\ z = \dfrac{33}{11} \\ \\ z = 3$

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$d) \\ 16x + 2. (7x8)-9+67$

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$e \\ 12+(3x+6).(-7)-5=70 \\ \\ 12 + (-21x - 42) - 5 = 60 \\ \\ 12 - 21x - 42 - 5 = 60 \\ \\ 12 -21x - 47 = 60 \\ \\ -21x - 35 = 60 \\ \\ - 21x = 60 + 35 *(-1)\\ \\ 21x = - 95 \\ \\ x = \dfrac{95}{21}$