Answer:
= cos4x
Explanation:
cosAcosB = [cos(A-B)+cos(A+B)]
Given: 2cos(2x)cos(2x)
= 2[cos(2x-2x)+cos(2x+2x)]
= 2cos4x^2
A = 210 + 20(h - 7) <== ur equation
if she earns 410 tutoring...
410 = 210 + 20(h - 7)
410 = 210 + 20h - 140
410 = 20h + 70
410 - 70 = 20h
340 = 20h
340/20 = h
17 = h <=== she spent 17 hrs tutoring
Answer:
i think a
Step-by-step explanation:
you said 10 i see five
The answer is 573
S is the three digit number.
h - a number of hundreds
t - a number of tens
o - a number of ones
S = 100h + 10t + o
<span>The last two digits add to make ten: t + o = 10
</span><span>The first and last digits add to make eight: h + o = 8
</span><span>The first two digits add to make twelve: h + t = 12
</span>t + o = 10 ⇒ o = 10 - t
h + o = 8 ⇒ o = 8 - h
_______
10 - t = 8 - h
h + t = 12 ⇒ h = 12 - t
_______
10 - t = 8 - (12 - t)
10 - t = 8 - 12 + t
10 - t = -4 + t
10 + 4 = t + t
2t = 14
t = 14/2 = 7
______
h = 12 - t = 12 - 7 = 5
______
o = 8 - h = 8 - 5 = 3
S = 100h + 10t + o
h = 5
t = 7
o = 3
S = 100*5 + 10*7 + 3
= 500 + 70 + 3
= 573
