Answer:
Step-by-step explanation:
All the angles in a triangle have to add up to 180 degrees.
#17.)
45+50=95
180-95=85
x=85
#18.)
This one is a little different. The furthest two angles are complimentary which means that they add up to 180 degrees (a straight line.) Once you find the missing angle to that one, you can do the same thing as you did in #17.
180-118=62.
25+62=87
180-87=93
x=93
#21.)
For this one a slightly larger equation is needed. Since we don't have a definite number for the bottom left angle, we have to use x+2 as our number. We first have to find the bottom right angle though.
180-108=72
x+x+2+72=180
2x+74=180
2x=106
x=53
Answer:A for the first one and C for the second one
Step-by-step explanation:
Answer:
12 teeth
Step-by-step explanation:
<em>The attachment of this question is missing; however, the question can be solved without the attachment</em>
Given:
Larger Gear = 6
Smaller Gear = 1
Required
Number of Smaller Gear if there are 72 larger gears
When the number of larger gear is 6, smaller gears is 1;
<em>This can be represented using the following ratio;</em>

Let x represent the number of smaller gear, when there are 72 larger gears;
<em>This can also be represented using the following ratio;</em>

Equate both ratios

Convert the ratios to fraction

Multiply both sides by x


Divide both sides by 6.



<em>This implies that there are 12 teeth on the smaller gear</em>
2x + 12 = 18
18 - 12 = 6
2x = 6
x = 3
If you put brackets around (2+1), your method of working is:
1) 15-4*(2+1)=3
2) 15-4*3=3
3) 15-12=3
You don't need any more brackets, as the BIDMAS (brackets, Indices, division, multiplication, addition, subtraction) rule does the rest of the job for you.
The answer is therefore: 15-4*(2+1)=3