Answer:
Step-by-step explanation:
3-(2x-5)=-4(x+2)
We simplify the equation to the form, which is simple to understand
3-(2x-5)=-4(x+2)
Remove unnecessary parentheses
3-2x+5=-4*(x+2)
Reorder the terms in parentheses
3-2x+5=+(-4x-8)
Remove unnecessary parentheses
+3-2x+5=-4x-8
We move all terms containing x to the left and all other terms to the right.
-2x+4x=-8-3-5
We simplify left and right side of the equation.
+2x=-16
We divide both sides of the equation by 2 to get x.
x=-8
D = {16, 19, 21}
E = {16, 18, 19, 20}
D ∩ E = {16, 19}
Responder:
<em>a) 1
</em>
<em>b) 12
</em>
<em>c) 3
</em>
<em>d) -1 y 3
</em>
Explicación paso a paso:
Dadas las siguientes ecuaciones;
a) x²-x =0
x² = 0+x
x² = x
x = 1
b) -x²+12x = 0
-x² = -12x
x² = 12x
x = 12
c) 3x² - 9x = 0
Suma 9x a ambos lados
3x²-9x+9x = 0+9x
3x² = 9x
3x = 9
x = 9/3
x = 3
d) x²-2x-3 = 0
x²-3x+x-3 = 0
x(x-3)+1(x-3) = 0
(x+1)(x-3) = 0
x+1 = 0 y x-3 = 0
x = -1 y 3
One month = 5000
Number of months before the spark plugs need to change :
15000 ÷ 5000 = 3
The sparks can last 3 months before it needs to be changed.
Number of times it need to change in a year = 12 ÷ 3 = 4
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Answer : It needs to be change 4 times a year.
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