Find the area.........

Find the value of “X”

marta [7]

Answer:

x = 55

Step-by-step explanation:

A triangle equals 180 degrees, b will be used to find the missing angle.

21 + 34 + b = 180

55 + b = 180

subtract 55 from both sides

b = 125

A straight line is 180 degrees and the b, the missing angle, and x are supplementary angles so

125 + x = 180

x = 55

3 0

3 years ago

The length of a rectangle is 3 centimeters less than four times its width. Its area is 10 square centimeters. Find the dimension

Kay [80]

Answer:

W = 2 cm

L = 5 cm

Step-by-step explanation:

A rectangle is a four sided shape with 4 perpendicular angles. It has two pairs of parallel sides which are equal in distance: width and length. Its area, the amount of space inside it, can be found using the formula A = l*w. If the area is 10 cm² and the length is "3 cm less than 4 times the width" or 4w - 3, you can substitute and solve for w.

A = l*w

10 = (4w - 3)(w)

10 = 4w² - 3w

Subtract 10 from both sides to make the equation equal to 0. Then solve the quadratic by quadratic formula.

4w² - 3w - 10 = 0

Substitute a = 4, b = -3 and c = -10.

$w = \frac{3 +/- \sqrt{(-3)^2 - 4(4)(-10)} }{2(4)} = \frac{3 +/- \sqrt{9 +160)} }{8} = \frac{3 +/- \sqrt{169} }{8} = \frac{3+/-13}{8}$

There are two possible solutions which can be found.

3 + 13 / 8 = 16/ 8 = 2

3 - 13 / 8 = -10/8 = -5/4

Since w is a side length or distance, it must be positive so w = 2 cm.

If the width is 2 cm then the length is 4(2) - 3 = 8 - 3 = 5 cm.

8 0

3 years ago

I DONT KNOW THESE! HELP!

kkurt [141]

Answer:

20. x = 5, y = -2

21. x = 11, y = 12

22. x = 22, y = 11

23. x = 11, y = 10

Step-by-step explanation:

20. Opposite sides in the parallelogram are congruent, so

$2y+18=3x-1\\ \\6x-3=17-5y$

Solve this system of two equations:

$\left\{\begin{array}{l}2y-3x=-19\\ \\6x+5y=20\end{array}\right.$

Multiply the first equation by 2 and add two equations:

$2(2y-3x)+6x+5y=2\cdot (-19)+20\\ \\4y-6x+6x+5y=-38+20\\ \\9y=-18\\ \\y=-2$

Substitute it into the first equation:

$2\cdot (-2)-3x=-19\\ \\-3x=-19+4\\ \\-3x=-15\\ \\x=5$

21. Opposite angles in the parallelogram are congruent, so

$11x+5=10y+6$

Consecutive angles are supplementary, so

$6x-y+11x+5=180^{\circ}$

Solve this system of two equations:

$\left\{\begin{array}{l}11x-10y=1\\ \\17x-y=175\end{array}\right.$

From the second equation

$y=17x-175$

Substitute it into the first equation:

$11x-10(17x-175)=1\\ \\11x-170x+1750=1\\ \\-159x=-1749\\ \\x=11\\ \\y=17\cdot 11-175=187-175=12$

22. Opposite angles in the parallelogram are congruent, so

$2x-5=3y-12$

Consecutive angles are supplementary, so

$2x-5+7y+x=180^{\circ}$

Solve this system of two equations:

$\left\{\begin{array}{l}2x-3y=-7\\ \\3x+7y=185\end{array}\right.$

From the first equation

$x=-3.5+1.5y$

Substitute it into the second equation:

$3(-3.5+1.5y)+7y=185\\ \\-10.5+4.5y+7y=185\\ \\-105+45y+70y=1,850\\ \\115y=1,850+105\\ \\115y=1,955\\ \\y=17\\ \\x=-3.5+1.5\cdot 17=22$

23. Opposite sides in the parallelogram are congruent, so

$2x+9=4y-9\\ \\3x-5=2y+8$

Solve this system of two equations:

$\left\{\begin{array}{l}2x-4y=-18\\ \\3x-2y=13\end{array}\right.$

Multiply the second equation by 2 and subtract it from the first equation:

$2x-4y-2(3x-2y)=-18-2\cdot 13\\ \\2x-4y-6x+4y=-18-26\\ \\-4x=-44\\ \\x=11$

Substitute it into the first equation:

$2\cdot 11-4y=-18\\ \\-4y=-18-22\\ \\-4y=-40\\ \\y=10$

3 0

3 years ago

( Identify the terms, their coefficients for each of the following expressions)

sweet-ann [11.9K]

Answer:

i. terms = 5xy(z)^2 , -3zy

coefficient = 5 and -3

ii. terms = 1 , X ,x^2

coefficient = 1 , 1

iv. terms = 3 , -pq , qr, -rp

coefficient = -1 ,1 , -1

v. terms = X/2 , y/2 , -xy

coefficient= 1/2 ,1/2 and -1

7 0

3 years ago

Use the Distributive Property to rewrite each expression. <br> 8 (2m + 1)

mestny [16]

Answer: 16m+8

Step-by-step explanation: 8 (2m + 1)

16m+8

5 0

3 years ago