Answer:
Question 4: -11
Question 5: -7
Step-by-step explanation:
Four
Every triangle has 180 degrees.
So all three angles add to 180
<em><u>Equation</u></em>
60 + 80 + x + 51 = 180
<em><u>Solution</u></em>
Combine the like terms on the left. This is the first time I've seen x be a negative value. Almost all of the time it isn't, which should make you wonder.
191 + x = 180
Subtract 191 from both sides.
191 - 191 + x = 180 - 191
x = - 11
Five
If a triangle is a right triangle and one of the angles is 45, then so is the other one.
<em><u>Proof</u></em>
a + 45 + 90 = 180 Combine like terms on the left
a + 135 = 180 Subtract 135 on both sides.
a + 135-135=180-135 Combine the like terms
a = 45
<em><u>Statement</u></em>
That means 52 + x = 45 and here is another negative answer. Subtract 52 from both sides
52 - 52 + x = 45 - 52 Combine like terms.
x = - 7
An equation that correctly represent this relationship if x represents the number of pounds of fertilizer and y the number of ounces of weed killer is 0.5x + 3.5y = 70
<u>Solution:</u>
Given that, Bill spent 70 on fertilizer and weed killer for his lawn
Each pound of fertilizer cost 50 cents and each once of weed killer cost 3.50
We have to write an equation, if x represents the number of pounds of fertilizer and y the number of ounces of weed killer.
Now,<em> total amount = amount for fertilizers + amount for weed killers.</em>
Total amount = number of pounds of fertilizers x cost per pound + number of ounces of weed killer x cost per ounce.

Hence, the equation is 0.5x + 3.5y = 70
6:45a to 7:45 = 1 hour
7:45 to 8:45 = 2 hours
8:45 to 9:45 = 3 hours
9:45 to 10:45 = 4 hours
10:45 to 11:45 = 5 hours
11:45 to 12:45 = 6 hours
12:45 to 1:45 = 7 hours
1:45 to 2:45 = 8 hours
2:45 to 3:00 = 8 hours and 15 minutes
then just add the 28 minutes to the 15 minutes
28 + 15 = 43
6:45a to 3:28p = 8 hours and 43 minutes.
Hope this helps.