Let x = your number.
x^2 - 21 = 4x. Subtract 4x from both sides.
x^2 - 4x - 21 = 0. Factor.
(x - 7) (x + 3) = 0. Set each term to 0.
x + 3 = 0. Subtract 3 from both sides.
x = -3. This is the negative solution.
Set the other term equal to zero.
x - 7 = 0. Add 7 to each side.
x = 7. This is the positive solution.
A perfect number is a number where the sum of its divisors is equal to the number.
For example 6: 1 + 2 + 3 = 6
Another example is 28: 1 + 2 + 4 + 7 + 14 = 28
Here is a short list of perfect numbers: 6, 28, 496, 8128, <span>33550336, and the numbers get way bigger as we go on.</span>
First, you should calculate the square footage of the fence.6ft∗300ft=1800ft2 Then to find the number of gallons of paint needed, divide the area of the fence by the area covered with each gallon of paint: 1800ft2÷400ft2=4.5 So, 4.5 gallons of paint, or rounding up, 5.
The mathematical functions (equations) are matched to their graph line respectively as follows:
- y = 960 - 78x: purple straight line.
- y = 8·3^x: violet line curve that slopes to the left.
- y = 960·(1/2)^x: green line curve that slopes to the right.
<h3>What is a linear function?</h3>
A linear function can be defined as a type of function whose equation is graphically represented by a straight line on the cartesian coordinate. Mathematically, a linear function is given by this equation:
y = mx ± c.
<h3>What is an exponential function?</h3>
An exponential function can be defined as a type of mathematical function whose values are generated by a constant that is raised to the power of the argument. Mathematically, an exponential function is represented by this formula:
f(x) = keˣ
Next, we would match each of the mathematical functions (equations) to their graph line respectively as follows:
- y = 960 - 78x: purple straight line.
- y = 8·3^x: violet line curve that slopes to the left.
- y = 960·(1/2)^x: green line curve that slopes to the right.
Read more on graphs here: brainly.com/question/24298987
#SPJ1
Hi there!
To find the perpendicular slope you need to flip the fraction and change the sign. So 1/2=2/1 and tge original slope was positive, so the slope is -2. Now you sub in the point (-7,-4) in for x and y in the formula y=mx+b and solve for b (sub in 2 for m as well)
Y=mx+b
-4=-2*-7+b
-4=14+b
-4-14=b
B=-18
The equation is y=-2x-18
Hope this helps!
