2x+38=180
2x=142 (or x+x=142 from which 2x=142)
x=71
The unknown angles are each 71
You know this answer is logical as, since two sides are 21 it hints that we are looking at an equilateral triangle, which means two of its angles will be the same
There are 72 tokens with Riley and 63 tokens with Erik
<em><u>Solution:</u></em>
Riley and Erik have earned a total of 135 tokens to buy items in the school store
Total number of tokens = 135
The ratio of the number of tokens that Riley had to the number of tokens that Erik has is 8 to 7
Number of tokens with Riley : Number of tokens with Erik = 8 : 7
Let the number of tokens with Riley be 8x
Let the number of tokens with Erik be 7x
Since, Total number of tokens = 135
number of tokens with Riley + number of tokens with Erik = 135
8x + 7x = 135
15x = 135
x = 9
Therefore,
Number of tokens with Riley = 8x = 8(9) = 72
Number of tokens with Erik = 7x = 7(9) = 63
Thus there are 72 tokens with Riley and 63 tokens with Erik
First you try and figure what times 2 =12 which would be what?
-9 and -12 are the answers
4. Let the numbers be x - 2, x, and x + 2, where x is an odd number.
2(x² - 4) - 4x = (x + 2)² + 21
2x² - 8 - 4x = x² + 4x + 4 + 21
2x² - 4x - 8 = x² + 4x + 25
x² - 8x - 33 = 0
(x - 11)(x + 3) = 0
x = 11, or -3
When x = 11, x - 2 = 9, x + 2 = 13
When x = -3, x - 2 = -5, x + 2 = -1
Explanation: You are on the right track. However, rather than having three unknown variables, try to reduce your working out to one unknown variable. Since you know they are consecutive odd numbers, you can simply let x be the middle term and the other two be + and - 2, provided x is an odd number.
That will reduce your variable issues, and helps as the first and third provide a difference of two squares, and this works out very nicely.
Q5: is essentially the same process. Let your variables be something in the form of one unknown variable, and you should be okay from there. Let me know if you're stuck.