Question

Cal calcule as equações seguintes a) x+5=20 b) 2x-4=10 c) 4x=60 d) 2x+6=12 e) 6x-4=2x+12 f)5x +6=x-8

Answer 1

$a) x+5=20\to x=20-5\to x=15 \\\\\\b) 2x-4=10\to 2x=10+4\to 2x=14\to x= \frac{14}{2} \to x=7 \\\\\\c) 4x=60 \to x= \frac{60}{4} \to x=15\\\\\\ d) 2x+6=12\to 2x=12-6\to 2x=6\to x= \frac{6}{2}\to x=3 \\\\\\e) 6x-4=2x+12\to 6x-2x=12+4\to 4x=16\to x= \frac{16}{4} \to x=4 \\\\\\f)5x +6=x-8\to 5x-x=-8-6\to 4x=-14\to x= \frac{-14}{4} \to\\ x=- \frac{7}{2}$

Answer 2

a) 
x + 5 = 20
 x = 20 - 5
x = 15
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b) 
2x - 4 = 10 
2x = 10 + 4
2x = 14
x = 14/2
x = 7
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c) 
4x = 60
x = 60/4
x = 15
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d) 
2x + 6 = 12 
2x = 12 - 6
2x = 6
x = 6/2
x = 3
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e) 
6x - 4 = 2x + 12 
6x - 2x = 12 + 4
4x = 16
x = 16/4
x = 4
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f)
5x + 6= x - 8 
5x - x = - 8 - 6
4x = - 14 (:2)
2x = - 7
x = - 7/2