100 = 2t + 4f
40= t + f
-----------
get t or f by itself first.
f = 40 - t : Then substitute it back into for f in the other equation
100 = 2t + 4f
100= 2t +4(40-t)
100= 2t + 160 - 4t
100 = -2t + 160
-160 -160
<u>-60 </u>= <u>-2t
</u>-2 -2
t = 30 (Then plug this into either equation to solve for f)
Therefore,
t = 30 questions
f = 10 questions
Comment
I'm going to take a guess at this and say what you meant is 2401 = 7^(6 - 2x)
Step One
Find out the power of 7 that will equal 2401.
You could do it like this.
7^y = 2401 and just guess at some values.
y 7^y
1 7
2 49
3 7 * 7 * 7 = 343
4 7 * 7 * 7 * 7 = 2401 So the answer is 4
7^4 = 2401
Step 2
Equate the powers.
2401 = 7^(6 - 2x)
7^4 = 7^ (6 - 2x)
4 = 6 - 2x Subtract 6 from both sides.
4 - 6 = - 2x
-2 = - 2x divide by - 2
-2/-2 = x
x = 1 <<<<<<<<<<<<<answer
Answer= 8/125 or 0.016
16/1000 can be simplified by dividing both the numerator and denominator by 8
16 2
____=___
1000 125
2/125=0.016
Answer:
18.9
Step-by-step explanation:
361-4 = 357
the root of 357 is 18.9 when rounded
