We write an inequality:



This equation cannot be solved using trivial methods found in high-school classes, so we resort to graphical examination.

is a linear function while

is an exponential one (with limit zero as

approaches

). We see that

at approximately

and

.
Indeed, using a computer algebra system such as the ones on modern TI calculators and on many internet sites gives equality at

. By observing our graph, we see that

when

or

.
Answer:
x≤-2
Step-by-step explanation:
To solve the inequality, we have to add 1 on each side:
5x-1≤11
+1 +1
And then we get:
5x≤-10.
To find x, we have to divide each side by 5:
5x/5≤-10/5
After we do that, we get:
x≤-2.
Joel = j, Mark = m, Sandra = s
j + m + s = 120
m = 3j
j = 1/2 s --> s = 2j
plug in (substitute) each letter to make it in terms of only j: j + m + s = 120
j + 3j + 2j = 120
6j = 120
6j/6 = 120/6
j = 20
now plug in for the j & s equation:
s = 2j = 2(20) = 40
Therefore Sandra has 40 coins!
16-3/4=15 1/4
You can convert to fractions first, and then convert back to a mixed number like:
16/1-3/4 and when you add/subtract fractions you need a common denominator
64/4-3/4
61/4
15 1/4
Or you can convert your fraction to a decimal to get:
16-0.75
15.25