17) 
18) 
19) 
20) 
Step-by-step explanation:
17) The difference between a number and 8 is 11
Let number = x
then the equation will be:

Solving:


18) Nine less than a number is five.
Let number = x
then the equation will be:

Solving:

19) Seven is equal to a number plus 6
Let number = x
then the equation will be:

Solving:

20) The sum of a number and -4 is -18
Let number = x
then the equation will be:

solving:

Keywords: Algebraic Expressions
Learn more about Algebraic Expressions at:
#learnwithBrainly
It is always a rational number
-Hope This Helps-
Highest mileage
m(s) = -0.025s2 + 2.45s - 30
This quadratic equation lokks like a upside down parabolla
So as it is a form of mileage gunction of speed, its maximum value should be K
The "a" in the vertex form "<span>y = a(x – h)2 + k</span>" of the quadratic is the same as the "a" in the common form of the quadratic equation, "<span>y = ax2 + bx + c</span><span>".
</span>
<span>To find the vertex, I look at the coefficients a<span>, </span>b<span>, and </span>c. The formula for the vertex gives me:<span>Y= -0.025s2 + 2.45s - 30
</span><span>h = <span>–b</span>/<span>2a</span> = -2.45/2× -0.025=49</span><span>Put value of h to get K</span><span>k=-0.025(49)^2+2.45×(49)-30</span><span>k= -30.025</span><span>k= -</span>30.0<span>
</span></span>
Answer: The price has gone up .07.
Step-by-step explanation:
07/2.80 x 100 = 2.5% increase