It is a linear simple equation for one unknown, lets solve it!
-4.2x + 31.5 = -65.1
we can easily get rid of decimals if we multiply the whole equation times 10:
<span>-42x + 315 = -651
</span>-42x = -651 - 315 = -966
x = 966/42
x = 23
that is the solution

7 0

4 years ago

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70 POINTS!! AND BRAINLIEST HELPPPPP!!!

DerKrebs [107]

Answer:

3000 girls
38 fishes
37 points
115 marbles
19 gray coloured cars

Step-by-step explanation:

Let the unknown values be x

30 class mates = 1 class room

18 girls in 1 classroom

18 girls in 30 classmates

x girls in 5000 class mates

$18\:girls= 30\:students\\x\:girls = 5000\:students\\\\Cross\:Multiply\\\\30x = 90000\\\\Divide\:both\:sides\:by\:30\\\frac{30x}{30} = \frac{90000}{30}\\ \\x = 3000\\= 3000 girls$

$2.5\:miles = 12 \:fishes\\8\:miles = x\:fishes\\\\Cross\:Multiply\\2.5x = 96\\\\Divide\:both\:sides\:of\:the\:equation\:by\:2.5\\\\\frac{2.5x}{2.5}=\frac{96}{2.5}\\ \\x = 38.4\\Approximately \: =38\:fishes$

$8\:minutes = 14\: points\\21 \:minutes = x \:points\\\\Cross\:Multiply\\8x = 294\\\\\mathrm{Divide\:both\:sides\:by\:}8\\\frac{8x}{8}=\frac{294}{8}\\\\Simplify\\x=\frac{147}{4}\\\\x = 36.75\\\\Approximately\:= 37\:points$

$32\:marbles = 5\:inches\\x\:marbles = 18\:inches\\\\Cross\:Multiply\\5x = 576\\\\\mathrm{Divide\:both\:sides\:by\:}5\\\frac{5x}{5}=\frac{576}{5}\\\\x=\frac{576}{5}\\\\x =115.2\\= 115=\:marbles$

$2 \: gray\:colour= 15\:cars\\x\:gray= 140\:cars\\\\Cross\:Multiply\\\\15x = 280\\\\\mathrm{Divide\:both\:sides\:by\:}15\\\frac{15x}{15}=\frac{280}{15}\\\\Simplify\\x=\frac{56}{3}\\\\x =18.666\\Approximately ;\\19$

6 0

4 years ago

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