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2 years ago

Solve for X and Y: Y=2+7x and -2x+6y=-28

Mathematics

1 answer:

Furkat [3]2 years ago

6 0

Answer:

x=-1 and y=-5

Step-by-step explanation:

ሰላም!

Given expressions let them given as two equations

y=2+7x....... equation (1)
-2x+6y=-28..... equation (2)

Thus, substitute y=2+7x into equation (2)

$- 2x + 6(2 + 7x) = - 28 \\$

simplify it

$- 2x + 12 + 42x = - 28 \\ 40x + 12 = - 28$

subtract 12 from both sides

$40x + 12 - 12 = - 28 - 12 \\ 40x = - 40$

divide both sides by 40

$\frac{40x}{40} = \frac{ - 40}{40} \\ x = - 1$

Therefore, as we get the value of x=-1 substitute it to equation (1) and solve for variable y

$y = 2 + 7x \\ y = 2 + 7( -1 ) \\ y = 2 - 7 \\ y = - 5$

To be more sure make a cross check on both of the two expressions

Thus,

1) y=2+7x .... substitute y=-5 and x=-1 and check if it is equal

-5=2+7(-1)

-5=2-5

-5=-5

2)-2x+6y=-28... substitute and check

-2(-1)+6(-5)=-28

2-30=-28... (-a)(-b)=ab

-28=-28

Hope it helps!

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What is the missing term in the pattern

olga_2 [115]

192. You multiply each answer with four, so it's 48x4=192. Hope this helps!

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4 years ago

Read 2 more answers

Help me solve this problem please

Mashutka [201]

Answer:

y = -2x + 17

Step-by-step explanation:

y has to equal 5:

incorrect

y = -2x - 17

y = -2(6) - 17

y = -12 - 17

y = -29

incorrect

y = -2x - 16

y = -2(6) - 16

y = -12 - 16

y = -28

incorrect

y = -2x + 16

y = -2(6) + 16

y = -12 + 16

y = 4

correct

y = -2x + 17

y = -2(6) + 17

y = -12 + 17

y = 5

8 0

4 years ago

Choose an expression that is equivalent to (-2)^4/(-2)^2. out of these

Marianna [84]

The expression that is equivalent to (-2)^4/(-2)^2 is (-2)^6/(-2)^4

<h3>How to determine the expression that is equivalent to (-2)^4/(-2)^2?</h3>

The expression is given as:

(-2)^4/(-2)^2

Apply the law of indices

(-2)^4/(-2)^2 = (-2)^(4 -2)

4 - 2 has the same value as 6 - 4

So, we have:

(-2)^4/(-2)^2 = (-2)^(6-4)

Apply the law of indices

(-2)^4/(-2)^2 = (-2)^6/(-2)^4

Hence, the expression that is equivalent to (-2)^4/(-2)^2 is (-2)^6/(-2)^4

Read more about equivalent expressions at:

brainly.com/question/2972832

#SPJ1

3 0

2 years ago

A collection of nickels and quarters is worth $4.65 there are three more nickels than quarters use a system of equations to dete

snow_lady [41]

Nickels = n
quarters = q
nX.05+qX.25 = 4.65
n is 3 greater than q
n = q+3
substitute n equal to 'q+3'

(q+3)X.05 + qX.25 = 4.65
.05q + .15 + .25q = 4.65
.30q + .15 = 4.65
.30q = 4.50
q = 4.50/.30 = 15
n = 15+3 = 18

There are 18 nickels and 15 quarters

4 0

3 years ago

You are given a 16-bit binary integer X= (1110 0100 0111 1010)2 . Convert X to decimal if:

podryga [215]

Step-by-step explanation:

a). The decimal numbers is equal to the sum of binary numbers $(b_n)$ times their powers of $2(2^n) .$

That is,

$b_n \times 2^n + b_{n-1} 2^{n-1}+ ..... + b_02^0$

$\therefore (1110 \ \ 0100 \ \ 0111 \ \ 1010)_2$

= $(0 \times 2^0) + (1 \times 2^1) + (0 \times 2^2) + (1 \times 2^3) + (1 \times 2^4) + (1 \times 2^5) + (1 \times 2^6) + ( 0 \times 2^7) + (0 \times 2^8) + (0 \times 2^9) + (1 \times 2^{10} )$ $+ (0 \times 2^{11}) + (0 \times 2^{12}) + (1 \times 2^{13}) + (1 \times 2^{14})+ (1 \times 2^{15})$

= 58490

b).

The left most bit of the number represents the sign of the number. If bit = 1, the number is negative else if the bit is 0, the number is positive.

All the remaining bits (i.e all the bits except the leftmost bit) represent the magnitude of the number.

Now, X = 1110 0100 0111 1010

left most bit = 1 => number is negative

remaining bits Y = 110 0100 0111 1010

converting Y to decimal => Y = 25722

c).

Check the leftmost bit(lmb) of the number

if leftmost bit is 0 => convert do the binary to decimal conversion

if leftmost bit is 1, follow the following steps

1. Flip the bits (convert the 0's into 1's and the vice versa)

2. convert the new number from binary to decimal.

3. Add a negative sign / multiply by -1

Now, X = 1110 0100 0111 1010

left most bit = 1;

flipping the bits => Y = 0001 1011 1000 0101

converting Y into decimal => Y = 7045

multiplying Y with -1 => Y = -7045

Therefore, one's complement of X to decimal is -7045

Thus, X = -25722 in decimal.

d).

Check the leftmost bit(lmb) of the number

if leftmost bit is 0 => convert do the binary to decimal conversion

if leftmost bit is 1, follow the following steps

1. Flip the bits (convert the 0's into 1's and the vice versa)

2. convert the new number from binary to decimal.

3. Add 1 to the converted number

4. Add a negative sign / multiply by -1

Now, X = 1110 0100 0111 1010

left most bit = 1;

flipping the bits => Y = 0001 1011 1000 0101

converting Y into decimal => Y = 7045

Adding 1 to Y => Y = 7046

multiplying Y with -1 => Y = -7046

Thus, two's complement of X to decimal is -7046

7 0

3 years ago