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3 years ago

3x+y=23, 6x-y=50, what is the value of x and y

Mathematics

1 answer:

Mice21 [21]3 years ago

4 0

Answer:

3x+y=23

6x-y=50

2(3x+y)=2(23)

6x+2y=46

(6x-y)-(6x+2y)=50-46

-3y=4

y=-4÷3

=-4/3

x=[23-(-4/3)]÷3

=24/1/3÷3

=73/3÷3

=73/9

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Deshaun's gas tank is 1/3 full. After he buys 3 gallons of gas, it is 1/2 full. How many gallons can Deshaun's tank hold?

rusak2 [61]

Answer:7 gallons

Step-by-step explanation:

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3 years ago

Monday: 10 apples and 5 bananas cost £4.20 Friday: 8 apples and 10 bananas cost £5.40 Find the cost of each - with an explanatio

motikmotik

Answer:

An apple costs £0.25

A banana costs £0.34

Step-by-step explanation:

Let a be apples and b be bananas.

10a+5b=4.2

8a+10b=5.4

Solve for a:

10a+5b=4.2

Subtract 5b from both sides

10a=4.2-5b

Subtract 4.2 from both sides

10a-4.2= -5b

Multiply both sides by -1

-10a+4.2=5b

8a+10b=5.4

Subtract 10b from both sides

8a=5.4-10b

Subtract 5.4 from both sides

8a-5.4= -10b

Multiply both sides by -1

-8a+5.4= 10b

Divide both sides by 2

-4a+2.7=5b

Combine equations:

-4a+2.7= -10a+4.2

Add 10a to both sides

6a+2.7=4.2

Subtract 2.7 from both sides

6a=1.5

Divide both sides by 6

a=0.25

An apple costs £0.25

Solve for b:

10a+5b=4.2

Subtract 10a from both sides

5b= -10a+4.2

Subtract 4.2 from both sides

5b-4.2= -10a

Multiply both sides by -1

-5b+4.2=10a

8a+10b=5.4

Subtract 8a from both sides

10b= -8a+5.4

Subtract 5.4 from both sides

10b-5.4= -8a

Divide both sides by 4

2.5b-1.35= -2a

Multiply both sides by 5

12.5b-6.75= -10a

Multiply both sides by -1

-12.5b+6.75=10a

Combine equations:

-12.5b+6.75= -5b+4.2

Add 12.5b to both sides

6.75=7.5b+4.2

Subtract 4.2 from both sides

2.55=7.5b

7.5b=2.55

Divide both sides by 7.5

b=0.34

A banana costs £0.34

If you would like to check and see if it is true, (I already checked, it is) you can use the formulas I gave at the start of the explanation.

10a+5b=4.2

8a+10b=5.4

a=0.25

b=0.34

3 0

3 years ago

Which point-slope equation represents a line that passes through (3, –2) with a slope of negative StartFraction 4 Over 5 EndFrac

Schach [20]

Answer:

y + 2 = (-4/5)(x - 3)

Step-by-step explanation:

Your slope is -4/5. Your line passes through (3, -2).

Applying the point slope formula, we get:

y + 2 = (-4/5)(x - 3)

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4 years ago

Read 2 more answers

What is the y-intercept of the line y=7?

Maru [420]

Answer:

Step-by-step explanation:

The value of the y-intercept is (0,7)

So the y intercept is 0,7

3 0

3 years ago

Round to the nearest tenth if necessary.

Andrei [34K]

Answer:

B) 25

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

Algebra I

Coordinates (x, y)

Algebra II

Distance Formula: $\displaystyle d = \sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$

Step-by-step explanation:

Step 1: Define

Identify

Point (-1, -8)

Point (-4, -4)

Step 2: Find distance d

Simply plug in the 2 coordinates into the distance formula to find distance d

Substitute in points [Distance Formula]: $\displaystyle d = \sqrt{(-4--1)^2+(-4--8)^2}$
[√Radical] (Parenthesis) Subtract: $\displaystyle d = \sqrt{(-3)^2+(4)^2}$
[√Radical] Evaluate exponents: $\displaystyle d = \sqrt{9+16}$
[√Radical] Add: $\displaystyle d = \sqrt{25}$
[√Radical] Evaluate: $\displaystyle d = 5$

4 0

3 years ago