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2 years ago

When evaluating the expression 5x^2 for x=4 explain why 4 must be squared before multiplying by 5

Mathematics

1 answer:

fenix001 [56]2 years ago

3 0

Answer:

Order of operations

Step-by-step explanation:

4 must be squared before multiplying by 5 because of order of operations (PEMDAS). PEMDAS stands for parentheses, exponents, multiplication, division, addition, and subtraction. 4 squared is an example of an exponent and multiplying by 5 is an example of multiplication. Therefore 4 squared must come first.

When 4 is squared first, you will get an answer of 80.

When you multiply by 5 first, you will get an answer of 400.

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After the outbreak of a mysterious disease the average wait time at a hospital increased by 70% before the outbreak the average

qaws [65]

Answer:

1.7m

Step-by-step explanation:

Given that 'm' was the waiting time before the outbreak

After the outbreak, waiting time increased by 70%.

This implies that :

70% of m increase

m + 70% of m

m + 70/100 of m

m + ( 70÷100 ) × m

m + 0.7m

= 1.7m

4 0

3 years ago

Solve the system of equations by substitution. 3/8 x + 1/3 y =17/24 and <br> x + 7y = 8

goblinko [34]

$\left \{ {{ \frac{3}{8}x+ \frac{1}{3}y = \frac{17}{14} } \atop {x+7y=8}} \right.$

To solve this system by substitution, first isolate x in the second equation.

$x+7y=8$
$x+7y-7y=8-7y$
$x=8-7y$

Now, plug this expression ( $8-7y$ ) for x in the top equation to solve for y.

$\frac{3}{8} (8-7y)+ \frac{1}{3} y= \frac{17}{14}$
$3- \frac{21}{8} y+ \frac{1}{3} y= \frac{17}{24}$
$72-63y+8y=17$
$72-55y=17$
$-55y=17-72$
$-55y=-55$
$y=1$

Now that you have y, plug it into the second equation and solve for x.

$x+7y=8$
$x+7(1)=8$
$x+7=8$
$x=1$

Last step is to plug your x- and y-values in to both equations to check your work.

$\frac{3}{8} (1)+ \frac{1}{3} y= \frac{17}{24}$

$\frac{3}{8} * \frac{3}{3} = \frac{9}{24} ; \frac{1}{3} * \frac{8}{8} = \frac{8}{24}$

$\frac{9}{24} + \frac{8}{24} = \frac{17}{24}$ <--True

$1+7(1)=8$
$1+7=8$ <--True

Answer:
$x=1 \\ y=1$

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3 years ago

What is the estimate of 8244 in the hundreds

yanalaym [24]

Answer:

Step-by-step explanation: Go on answer.com if no one knows it on here. Hope this helps!!

7 0

2 years ago

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Follow the directions to solve the system of equations by elimination.

omeli [17]

Answer:

X= 1/2 Y= 5

Step-by-step explanation:

8x+7y=39-------------(1)--------×2

4x-14y= -68-----------(2)-------×1

16X + 14Y = 78--------(3)

4X- 14Y = -68----------(4)

Addy equation (4) and (3)

20X = 10

dividing bothsides by 20

20X/20= 10/20

X = 1/2

substitute the value of X into equation (1)

8X+7Y = 39

8(1/2)+7Y= 39

4+7Y = 39

7Y = 39-4

7Y = 35

dividing bothsides 7

7Y= 35/7

Y = 5

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1 year ago

Helppoo 10 points! I’ll mark brainliest!

77julia77 [94]

Answer Yes, because you take the answer from 100+45 and subtract 3 to get to 97 and then you add 29 to make the 47 a 74.

Step-by-step explanation:

4 0

2 years ago

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