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3 years ago

Drag each equation to show if it could be a correct first step to solving the equation

Mathematics

1 answer:

kirill [66]3 years ago

4 0

Answer:

4+4x=20

4x=20-4

4x=16

x=16/4

x=16

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Vicki is 5 years older than twice Ella's age, a.

Anettt [7]

Answer:

5+3a=29

Step-by-step explanation:

let Ella's age be 'a'

Vicki's age=5+2a

sum of their ages= 29

So, the equation is

(5+2a)+a=29

5+3a=29

hope this helps!

8 0

3 years ago

Read 2 more answers

If a person starts investing $100 per month starting at age 21, and that money earns a 5% return every year, how much will this

aalyn [17]

The formula for calculating compound interest with yearly contributions is:

Balance = X*(1 + Y)^n + Z((1 + Y)^(n + 1) - (1 + Y)/Y)

where the balance is the money earned after n years invested

Y is the interest rate as a fraction

Z is the yearly contribution

X is the starting investment

Therefore the calculation for this example is:

Balance = 1200*(1 + 0.05)^48 + 1200((1.05)^49 - (1.05)/05)

= $249,393.5

8 0

4 years ago

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At the market, 9 apples cost $4.00. How much does 10 apples cost?

ycow [4]

Answer:

$6.25

Step-by-step explanation:

Each apple is 2.25

6 0

3 years ago

Answer this question

lutik1710 [3]

Answer:

Step-by-step explanation:

1. Eggs are sold at a price of P 105.00 per dozen.

Rate = $\frac{1}{105}$

2. The carpentry job can be done by 3 carpenters in 4 days.

Rate at which each carpenter works = $\frac{4}{3}$ = 1 $\frac{1}{3}$ days

This shows that each carpenter worked for an average of 1.3333 days to complete the job.

3. Five tickets are sold at P 600.00

The price for one ticket = $\frac{600}{5}$

= 120

One ticket is sold for P 120.00.

4. The dollar's rate is P 52.00.

This implies that;

1 dollar = P 52.00

dollar rate = $\frac{1}{52}$

5. The ratio of water to milk in the recipe is 1 to 4.

This implies that to 1 measure of water, 4 measures of milk is used in the recipe.

rate = $\frac{1}{4}$

5 0

3 years ago

An electronics company produces transistors, resistors, and computer chips. Each transistor requires 3 units of copper, 1 unit

padilas [110]

Answer:

An electronics company can be produce 350 transistors and 340 computer chips, they can´t produce resistors.

Step-by-step explanation:

1. We will name the variables for transistors, resistors and the computer chips.

a = Transistors

b= Resistors

c = Computer chips

2. We propose three linear equations, one for the copper, one for the zinc and one for the glass.

$\left \{ {{3a+3b+2c=1730} \atop {a+2b+c=690}}\atop {2a+b+2c=1380}} \right.$

3. We write the matrix form as Ax=d

$A=\left(\begin{array}{ccc}3&3&2\\1&2&1\\2&1&2\end{array}\right)$

$x=\left(\begin{array}{ccc}a\\b\\c\end{array}\right)$

$A=\left(\begin{array}{ccc}1730\\690\\1380\end{array}\right)$

With this formula the solution of x is $x=\frac{d}{A}$ or $x=A^{-1}d$

4. We will find the inverse matrix $A^{-1}$ using the formula:

$A^{-1} = \frac{1}{detA} (C_{A})^{T}$

a. det A

$det A=\left[\begin{array}{ccc}3&3&2\\1&2&1\\2&1&2\end{array}\right] =3*(4-1)-3*(2-2)+2*(1-4)=9-0-6=3$

b. $(C_{A})^{T}$

$C_{A}=\left(\begin{array}{ccc}4-1&.(2-2)&1-4\\-(6-2)&6-4&-(3-6)\\3-4&-(3-2)&6-3\end{array}\right)$

$C_{A}=\left(\begin{array}{ccc}3&.0&-3\\-4&2&3\\-1&-1&3\end{array}\right)$

$(C_{A}) ^T=\left(\begin{array}{ccc}3&0&-3\\-4&2&3\\-1&-1&3\end{array}\right)^T$

$(C_{A}) ^T=\left(\begin{array}{ccc}3&-4&-1\\0&2&-1\\-3&3&3\end{array}\right)$

c. $A^{-1}$

$A^{-1}=\frac{1}{3} \left(\begin{array}{ccc}3&-4&-1\\0&2&-1\\-3&3&3\end{array}\right)$

5. As $x=\frac{d}{A}$ or $x=A^{-1}d$ , the solution of x is:

$x=\frac{1}{3}\left(\begin{array}{ccc}3&-4&-1\\0&2&-1\\-3&3&3\end{array}\right)\left(\begin{array}{ccc}1730\\690\\1380\end{array}\right)$

$x=\frac{1}{3}\left(\begin{array}{ccc}(3*1730)+(-4*690)+(-1*1380)\\(0*1730)+(2*690)+(-1*1380)\\(-3*1730)+(3*690)+(3*1380)\end{array}\right)$

$x=\frac{1}{3}\left(\begin{array}{ccc}1050\\0\\1020)\end{array}\right)$

$X=\left[\begin{array}{ccc}350\\0\\340\end{array}\right]$

Therefore:

a= 350 Transistors

b=0 Resistors

c=340 Computer chips

4 0

3 years ago