d) You have a <u>difference of squares</u>:
49y² - 9 = (7y)² - 3²
Recall the identity,
a² - b² = (a - b) (a + b)
So,
49y² - 9 = (7y - 3) (7y + 3)
e) Pull out the common factor 3 from each term:
3x² - 3x - 90 = 3 (x² - x - 30)
Now use the <u>sum-product method</u>. Notice that we can write 30 = 5 • 6, and 5 - 6 = 1, so
3x² - 3x - 90 = 3 (x + 5) (x - 6)
f) Same as in (e), use the <u>sum-product method</u>. Notice that 42 = 7 • 6, and -7 - 6 = -13, so
x² - 13x + 42 = (x - 7) (x - 6)
Answer:
a screw is a simple machine that works as a modified inclined plane. You can think of the thread of the screw as an inclined plane wrapped around the shaft of the screw. The slope of the screw is the distance for one complete rotation while the height of the inclined plane is the distance between the threads, known as pitch. The relationship between the pitch and circumference of the screw gives the mechanical advantage.
Step-by-step explanation:
Given expression is;
Solving for 
Multiplying both sides by 2
Dividing both sides by h
Subtracting 
from both sides
Keywords: division, subtraction
Learn more about subtraction at:
#LearnwithBrainly
Given :
Rain is falling at 0.5 inches per hour and 1.5 inches have already accumulated.
To Find :
How many hours must have passed if there are 5 inches of rain .
Solution :
Let , after x hours rain accumulated is 5 inches .
We know , general equation of line :
y = mx +c
Here , m = 0.5 and c = 1 .
So , equation of rain accumulated is :
Now , putting value of x = 5 hours .
We get :
Hence , this is the required solution .
Answer:
The correct answer is option A. Base = 11 cm and height = 13 cm
Step-by-step explanation:
It is given that, height of a triangle is 2 cm more than its base.Then height is increased by 2 cm.Then the area of triangle becomes 82.5 cm²
<u>To find the base an d height of original triangle</u>
Let x be the original base 'b' then the height h = x + 2
New height h = x + 2 + 2 = x + 4
Area = bh/2
82.5= (x(x + 4)/2
165 = x² + 4x
x + 4x - 165 = 0
Solving we get x = 11 and x = -15
Take positive value x = 11
Therefore base = 11 and height = x + 2 = 13 cm
The correct answer is option A. Base = 11 cm and height = 13 cm
