It looks as though there are 25 21-40 year-olds. 40% of 25 is 10, this is the amount that are AGAINST the increase. Therefore the ones in favor for the increase must be 25 - 10 = 15.
You should be able to follow the same process to get the 41-60 year-olds against an increase. Just be sure to read the given information carefully
Let <em>a</em> and <em>b</em> be the two numbers. Then
<em>a</em> + <em>b</em> = -4
<em>a b</em> = -2
Solve the second equation for <em>b</em> :
<em>b</em> = -2/<em>a</em>
Substitute this into the first equation:
<em>a</em> - 2/<em>a</em> = -4
Multiply both sides by <em>a</em> :
<em>a</em>² - 2 = -4<em>a</em>
Move 4<em>a</em> to the left side:
<em>a</em>² + 4<em>a</em> - 2 = 0
Use the quadratic formula to solve for <em>a</em> :
<em>a</em> = (-4 ± √(4² - 4(-2))) / 2
<em>a</em> = -2 ± √6
If <em>a</em> = -2 + √6, then
-2 + √6 + <em>b</em> = -4
<em>b</em> = -2 - √6
In the other case, we end up with the same numbers, but <em>a</em> and <em>b</em> are swapped.
Answer:
scale factor 3 is the answer.
Step-by-step explanation:
Length = 18 in
Breadth = 3 in
height = 10 in
Volume of cuboid = l × b × h
V = 18 × 3 × 10
V = 540 in³
540 in³ is the original volume. The volume needs to be tripled, so multiply the original volume with 3
V = 540 × 3 = 1620 in³
∴ 1620 in³ will be the new volume if it's tripled and the scale factor is 3.
