Answer:
second option
Step-by-step explanation:
Given
+ 6x² + 5 = 0
let u = x², then
u² + 6u + 5 = 0 ← in standard form
(u + 1)(u + 5) = 0 ← in factored form
Equate each factor to zero and solve for u
u + 1 = 0 ⇒ u = - 1
u + 5 = 0 ⇒ u = - 5
Change u back into terms of x, that is
x² = - 1 ( take the square root of both sides )
x = ± = ± i ( noting that
= i ), and
x² = - 5 ( take the square root of both sides )
x = ± = ±
= ±
×
= ± i
Solutions are x = ± i and x = ± i
Answer:
1. 10 square yards
2. $9.10
3. 36 girls
4. 20 cherries
5. 159 bracelets
Step-by-step explanation:
1.
The area of this figure would be the area of the SQUARE minus the area of the RECTANGLE (taken out).
The middle part is taken out (this is a rectangle).
View this as a square with sides 4 by 4 with a rectangle portion taken out. So the area can be said as:
Area = Area of Whole Square - Area of Middle Rectangle Taken Out
Lets calculate:
Area of Whole Square:
side * side = 4 * 4 = 16
Now,
Area of Middle Rectangle Taken Out:
Length * Width
The length is given as 3
The width would be 4 - two 1 from two sides, that is 4 - 1 - 1 = 2
So, area = 3 * 2 = 6
Area of figure = 16 - 6 = 10 square yards
2.
We have to find 20% of the bill.
The bill was 45.50 and we have to find 20% of 45.50.
We first convert percentage to decimal by dividing by 100:
20% = 20/100 = 0.20
Now we multiply this decimal with the bill to get our desired answer:
0.20 * 45.50 = $9.10
The tip is $9.10
3.
The ratio of boys (b) to girls (g) would be 2 is to 3.
There are 24 boys.
We can set up a ratio (fraction) with boys on top and girls on bottom.
Then we equate it with actual number of boys and girls (let it be g). So the ratio set-up would be:
To solve for g, the number of girls, we have to cross multiply and use algebra to solve. The process is shown below:
There are 36 girls in sixth grade
4.
For every "9" lemon, there are "4" cherries.
There are 45 lemons
If we think of "9" lemons as a "box", how many boxes of lemons are there?
45/9 = 5
Similarly, there would be "5" boxes of cherries. But there are "4" cherries per box. So there are:
4 * 5 = 20 cherries
We can also set up a ratio of cherry to lemon as 4 is to 9 and equate it with actual cherries (let it be "c") and lemons (45). Cross multiply and use algebra to solve for cherries ("c"). Algebra process shown below:
See, we have the same answer, 20 cherries!
5.
Number sold total = 14 + 27 + 45 = 86
She still has 73 in her stock
So, she basically started with whatever she now has (73) and whatever she has sold the 3 days (86), that would be:
73 + 86 = 159 bracelets
Tia started with 159 bracelets