The answers are :
10) 25 : 24
11) 24 : 5
12) 36 : 5
13) 7 : 3
14) 15 : 1
<u>Ratio = Number of event 1 : Number of event 2</u> (in same unit, if necessary)
<u>10</u>
Girls preferring orange juice : Boys preferring orange juice
50 : 48 (Divide by 2 on both sides)
25 : 24
<u>11</u>
Boys preferring orange juice : Boys preferring grapefruit juice
48 : 10 (Divide by 2 on both sides)
24 : 5
Remember :
- <u>1 minute = 60 seconds</u>
- <u>1 week = 7 days</u>
- <u>1 hour = 60 minutes</u>
<u />
<u>12</u>
3 minutes : 25 seconds
3 × 60 : 25 (Divide by 5 on both sides)
3 × 12 : 5
36 : 5
<u>13</u>
2 weeks : 6 days
2 × 7 : 6 (Divide by 2 on both sides)
7 : 3
<u>14</u>
5 hours : 20 minutes
5 × 60 : 20 (Divide by 20 on both sides)
5 × 3 : 1
15 : 1
<span>The <u>correct answers</u> are:
x=-3 and x=-8.
Explanation<span>:
We can first write this in standard form, ax</span></span>²<span><span>+bx+c=0. To do this, we will add 11x to both sides:
x</span></span>²<span><span>+24+11x=-11x+11x
x</span></span>²<span><span>+11x+24=0.
Now we can factor this. Look for factors of c, 24, that sum to b, 11. Factors of 24 are:
1 and 24 (sum 25)
2 and 12 (sum 14)
3 and 8 (sum 11)
4 and 6 (sum 10).
The factors we need are 3 and 8, since they sum to 11. This gives us factored form:
(x+3)(x+8)=0.
Using the zero product property, we know that in order to have a product of 0, one or both of the factors must be 0. This means we have:
x+3=0 or x+8=0.
Solving the first equation:
x+3-3=0-3
x=-3.
Solving the second equation:
x+8-8=0-8
x=-8.</span></span>
<h2>1)</h2>
This must be true for some value of x, since we have a quantity squared yielding a positive number, and since the equation is of second degree,there must exist 2 real roots.
<h2>2)</h2>
Well he started off correct to the point of completing the square.
