Since we want it in the form: (x - a)², let's first expand (x - a)² and then equate for the coefficients.
(x - a)² = x² - 2ax + a²
x² + 4x - 15 = x² - 2ax + a²
Now, let's focus on the middle term.
4x = -2ax
4 = -2a
a = -2
Thus, we know that a = -2
Then, we can say (x + 2)² = x² + 4x - 15
x² + 4x + 4 = x² + 4x - 15
Thus, 19 units are needed in order to complete the square to produce:
(x + 2)²
When x= 2 the corresponding y value is 6, according to the point 2,6
Answer: Area = 6m²
Smaller number = 16
Hours = 9.6 h
Step-by-step explanation:
A rectangle is 5 meters longer than its width. If the length is shortened by 2 meters and width is increased by 1 meter, the area remains the same. Find the area of the rectangle.
1) w = x m 2) w = x + 1 m
l = x + 5 m l = x + 5 - 2 = x + 3 m
A₁ = A₂
A = w*l
A₁ = x(x+5) = x² + 5x
A₂ = (x+1)(x+2) = x² + x + 2x + 2 = x² + 3x + 2
A₁ = A₂
x² + 5x = x² + 3x + 2
5x - 3x = 2
2x = 2
x = 1
A₁ = x(x+5) = 1.6 = 6 m²
The ratio of two numbers is 2:5. If the larger number is 40, what is the smaller number.
<u> 2 </u> = <u> x </u>
5 40
5x = 80
x = 80/5 = 16
Sixteen construction workers can finish cementing a floor of a building in 3 hours. On a certain day, only 5 construction workers are available for the job. How long will it take the 5 construction workers to do the cementing job?
workers hours
16 3
5 x
↑ ↓ inversely proportional
<u> 5 </u> = <u> 3 </u>
16 x
5x = 16*3
5x = 48
x = 48/5
x = 9.6 h
Answer:
7.87X10^3
Step-by-step explanation:
^ means to the power of
Answer:
The value of y would be 45.5
Step-by-step explanation:
To solve this problem, start with the base form of direct variation.
y = kx
Now we can use our original values to model the equation and find k.
35 = k(2.5)
14 = k
Now we can model the equation as:
y = 14x
Now to find y, when x = 3.25, simply put 3.25 into the equation.
y = 14(3.25)
y = 45.5
