Translate this phrase into an algebraic expression.

Solve the following using Substitution method 2x – 5y = -13 3x + 4y = 15

Digiron [165]

$\huge \boxed{\mathfrak{Question} \downarrow}$

Solve the following using Substitution method

2x – 5y = -13

3x + 4y = 15

$\large \boxed{\mathfrak{Answer \: with \: Explanation} \downarrow}$

$\left. \begin{array} { l } { 2 x - 5 y = - 13 } \\ { 3 x + 4 y = 15 } \end{array} \right.$

To solve a pair of equations using substitution, first solve one of the equations for one of the variables. Then substitute the result for that variable in the other equation.

$2x-5y=-13, \: 3x+4y=15$

Choose one of the equations and solve it for x by isolating x on the left-hand side of the equal sign. I'm choosing the 1st equation for now.

$2x-5y=-13$

Add 5y to both sides of the equation.

$2x=5y-13$

Divide both sides by 2.

$x=\frac{1}{2}\left(5y-13\right) \\$

Multiply $\frac{1}{2}\\$ times 5y - 13.

$x=\frac{5}{2}y-\frac{13}{2} \\$

Substitute $\frac{5y-13}{2}\\$ for x in the other equation, 3x + 4y = 15.

$3\left(\frac{5}{2}y-\frac{13}{2}\right)+4y=15 \\$

Multiply 3 times $\frac{5y-13}{2}\\$ .

$\frac{15}{2}y-\frac{39}{2}+4y=15 \\$

Add $\frac{15y}{2} \\$ to 4y.

$\frac{23}{2}y-\frac{39}{2}=15 \\$

Add $\frac{39}{2}\\$ to both sides of the equation.

$\frac{23}{2}y=\frac{69}{2} \\$

Divide both sides of the equation by 23/2, which is the same as multiplying both sides by the reciprocal of the fraction.

$\large \underline{ \underline{ \sf \: y=3 }}$

Substitute 3 for y in $x=\frac{5}{2}y-\frac{13}{2}\\$ . Because the resulting equation contains only one variable, you can solve for x directly.

$x=\frac{5}{2}\times 3-\frac{13}{2} \\$

Multiply 5/2 times 3.

$x=\frac{15-13}{2} \\$

Add $-\frac{13}{2}\\$ to $\frac{15}{2}\\$ by finding a common denominator and adding the numerators. Then reduce the fraction to its lowest terms if possible.

$\large\underline{ \underline{ \sf \: x=1 }}$

The system is now solved. The value of x & y will be 1 & 3 respectively.

$\huge\boxed{ \boxed{\bf \: x=1, \: y=3 }}$

8 0

2 years ago

Does anyone know the answer to this?

Alex

Answer:

10.5.

Step-by-step explanation:

By similar triangles:

IJ / 21 = 8 /(8+8) = 1/2

IJ / 21 = 1/2

IJ = 1/2 * 21

= 10.5.

6 0

2 years ago

The circumference of ruby's old swimming pool is 47.1 feet. Her new swimming pool has a diameter of 21 feet. How much larger is

Alla [95]

The new pool is 18.84 feet larger in circumference than the old one.

Explanation:

Given:

Circumference of the pool = 47.1 feet

Diameter of the new pool, d = 21 feet

radius, r = 21/2 feet

Circumference of the new pool = ?

We know:

Circumference = 2πr

where,

r is the radius

On substituting the value:

C = $2 X 3.14 X \frac{21}{2}$

C = 65.94 feet

The difference in circumference of the two pools = 65.94 - 47.1 feet

= 18.84 feet

Therefore, the new pool is 18.84 feet larger in circumference than the old one.

6 0

3 years ago

Long division (4b^3+10b^2-32b+15) divided by (4b-6)

MrMuchimi

Answer:

4b^3 + 10b^2 - 32b + 15

___________________

2(2b - 3)

Step-by-step explanation:

Take out the greatest common factor of (4b - 6) which is 2 and 3.

8 0

3 years ago

What is measure of angle KJL

Xelga [282]

Answer:

7x - 8.

Step-by-step explanation:

sad face

5 0

3 years ago