Question

Ajuda por favor ??????

Answer 1

Resposta:

1) $x=3$

2) $x=6$

3) $a=4$

4) $y=-8$

5) $x=1$

6) $x=2$

7) $x=12$

8) $x=10$

Explicação passo-a-passo:

1)

$X+5=8\\X=8-5\\X=3$

2)

$3x+2=20\\\\3x=20-2\\\\3x=18\\\\x=18/3\\\\x=6$

3)

$-2a=-8\\\\a=\frac{-8}{-2}\\\\a=4$

4)

$10-2y=26\\\\-2y=26-10\\\\-2y=16\\\\y=\frac{16}{-2} \\\\y=-8$

5)

$5x-6=-3x+2\\\\5x +3x=2+6\\\\8x=8\\\\x=8/8\\\\x=1$

6)

$5x-2(x-7)-6=14\\\\5x-2(x-7)=14+6\\\\5x-2(x-7)=20\\\\5x-2(x-7)=20\\\\5x-2x+14=20\\\\3x=20-14\\\\3x=6\\\\x=6/3\\\\x=2$

7)

$1+\frac{3x}{4} =10\\\\\frac{3x}{4} =10-1\\\\\frac{3x}{4} =9\\\\3x=9*4\\\\3x=36\\\\x=36/3\\\\x=12$

8)

$\frac{2x-15}{10} =\frac{x-9}{2} \\\\10*\frac{2x-15}{10} =10*\frac{x-9}{2} \\\\\\2x-15=5(x-9)\\\\2x-15=5x-45\\\\-15+45=5x-2x\\\\30=3x\\\\x=30/3\\\\x=10$

Answer 2

Explicação passo-a-passo:

$1)\\ x+5=8\\ x=8-5\\ x=3\\ S=\{3\}$

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$2)\\ 3x+2=20\\ 3x=20-2\\ 3x=18\\\\ x={18\over3}\\\\ x=6\\ \\ S=\{6\}$

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$3)\\ -2a=-8~~~\times(-1)\\ 2a=8\\ a=8\div2\\ a=4\\ \\ S=\{4\}$

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$4)\\ 10-2y=26\\ -2y=26-10\\ -2y=16\\ \\ y=16\div(-2)\\ y=-8\\ \\ S=\{-8\}$

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$5)\\ 5x-6=-3x+2\\ 5x+3x=2+6\\ 8x=8\\ \\ x={8\over8}\\ \\ x=1\\ \\ S=\{1\}$

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$6)\\ 5x-2(x+1)-6=14\\ 5x-2x-2-6=14\\ 5x-2x-8=14\\ \\ 3x=14+8\\ 3x=22\\ \\ x={22\over3}\\ \\ S=\{{22\over3}\}$

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$7)\\ 1+{3x\over4}=10\\ \\ mmc=4\\ \\ 4+3x=40\\ 3x=40-4\\ 3x=36\\ x=36\div3\\ \\ x=12\\ \\ S=\{12\}$

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$8)\\ {2x-15\over10}={x-9\over2}\\ \\ multiplica~~cruzado\\ \\ 10.(x-9)=2.(2x-15)\\ 10x-90=4x-30\\ 10x-4x=-30+90\\ 6x=60\\ \\ x={60\over6}\\ \\ x=10\\ \\ S=\{10\}$