All categories

3 years ago

Find a and b from the picture

Mathematics

1 answer:

Anni [7]3 years ago

5 0

Answer:a is 40 degrees

b is 140 degrees

Step-by-step explanation:

The given polygon has 5 irregular sides. This means that it is an irregular pentagon. The sum of the exterior angles of a polygon is 360 degrees

The exterior angles of the given pentagon are a, 75, 65, 60 and 120. Therefore

a + 75 + 65 + 60 + 120 = 360

a + 320 = 360

Subtracting 320 from both sides of the equation, it becomes

a = 360 - 320 = 40 degrees

The sum of angles on a straight line is 180/degrees. Therefore,

a + b = 180

b = 180 - a = 180 - 40 = 140 degrees

You might be interested in

: Which equations have an infinite number of solutions? Select all that apply. A -2(x - 2) + 3x = x - 4 B 2x + 4(x - 1) = 3(2x +

MissTica

Option C and Option D

3x + 2(x - 2) + 6 = 2(2x + 3) + x - 4 has infinite number of solutions

4(x + 2) + x + 1 = 2x - 3 + 3(x + 4) has infinite number of solutions

<h3><u>Solution:</u></h3>

Given that we have to find the equations that has infinite number of solutions

If we end up with the same term on both sides of the equal sign, such as 4 = 4 or 4x = 4x, then we have infinite solutions.

If we end up with different numbers on either side of the equal sign, as in 4 = 5, then we have no solutions.

<h3><u>Option A</u></h3>

-2(x - 2) + 3x = x - 4

Multiply the terms inside the bracket

-2x + 4 + 3x = x - 4

x + 4 = x - 4

Thus this equation does not have infinite number of solutions

<h3><u>Option B</u></h3>

2x + 4(x - 1) = 3(2x + 1) - 2(x - 1)

2x + 4x - 4 = 6x + 3 - 2x + 2

6x - 4 = 4x + 5

6x - 4x = 5 + 4

2x = 9

$x = \frac{9}{2}$

Thus this equation has only one solution.

Thus this equation does not have infinite number of solutions

<h3><u>Option C</u></h3>

3x + 2(x - 2) + 6 = 2(2x + 3) + x - 4

3x + 2x - 4 + 6 = 4x + 6 + x - 4

5x + 2 = 5x + 2

Thus this equation has infinite number of solutions

<h3><u>Option D</u></h3>

4(x + 2) + x + 1 = 2x - 3 + 3(x + 4)

4x + 8 + x + 1 = 2x - 3 + 3x + 12

5x + 9 = 5x + 9

Thus this equation has infinite number of solutions

3 0

4 years ago

If logb2=x and logb3=y, evaluate the following in terms of x and y:

Alja [10]

$log_b{162} = x + 4y\\\\log_b324 = 2x+4y\\\\log_b\frac{8}{9} = 3x-2y\\\\\frac{log_b27}{log_b16} = 3y-4x$

<em><u>Solution:</u></em>

Given that,

$log_b2 = x\\\\log_b3 = y --------(i)$

<em><u>Use the following log rules</u></em>

Rule 1: $log_b(ac) = log_ba + log_bc$

Rule 2: $log_b\frac{a}{c} = log_ba - log_bc$

Rule 3: $log_ba^c = clog_ba$

$a) log_b{162}$

Break 162 down to primes:

$162 = 2^1 \times 3^4$

$log_b{162} =log_b 2^1. 3^4\\\\By\ rule\ 1\\\\ log_b{162} = log_b 2^1 +log_b 3^4\\\\By\ rule\ 3\\\\1log_b2 + 4log_b3\\\\1x+4y\\\\x+4y$

Thus we get,

$log_b162 = x + 4y$

$b) log_b 324$

Break 324 down to primes:

$324 = 2^2 \times 3^4$

$log_b324 = log_b 2^2.3^4\\\\By\ rule\ 1\\\\log_b324 = log_b2^2 + log_b3^4\\\\By\ rule\ 3\\\\log_b324 = 2log_b2 + 4log_b3\\\\From\ (i)\\\\log_b324 = 2x + 4y$

$c) log_b\frac{8}{9}$

By rule 2

$log_b\frac{8}{9} = log_b8 - log_b9\\\\log_b\frac{8}{9} = log_b 2^3 - log_b3^2\\\\By\ rule\ 3\\\\log_b\frac{8}{9} = 3 log_b2 - 2log_b3\\\\From\ (i)\\\\log_b\frac{8}{9} = 3x - 2y$

$d) \frac{log_b27}{log_b16}$

By rule 2

$\frac{log_b27}{log_b16} = log_b27 - log_b16\\\\ \frac{log_b27}{log_b16} = log_b3^3 - log_b2^4\\\\By\ rule\ 2\\\\ \frac{log_b27}{log_b16} = 3log_b3 - 4log_b2 \\\\From\ (i)\\\\\frac{log_b27}{log_b16} = 3y - 4x$