Answer:
75
Step-by-step explanation:
Let t and u represent the tens and units digits, respectively.
t = u + 2 . . . . the tens digit exceeds the units digit by 2
t + 2u = 17 . . . . the sum of the tens digit and twice the units digit is 17
Substituting for t in the second equation, we get ...
(u +2) +2u = 17
3u = 15 . . . . . . . . subtract 2
u = 5 . . . . . . . . . . divide by 3
t = u+2 = 7
The number is 75.
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<em>Check</em>
7 exceeds 5 by 2. 7 + twice 5 = 7 + 10 = 17.
1. 0.91<0.93; 0.91 is farther away from the whole number 1 so it is less than 0.93.
2. 0.5=0.50; 0.5 and 0.50 are the same, since the decimal can be written with or without the zero.
3. 1.08<1.6; 1.08 is farther away from the whole number 2, so it is less than 1.6.
Answer:
5. x = -1
6. x = 2
Step-by-step explanation:
5. AB = 5
BC = 2x + 6
AC = x + 10
AB + BC = AC (segment addition postulate)
5 + 2x + 6 = x + 10 (substitution)
Collect like terms
5 + 6 + 2x = x + 10
11 + 2x = x + 10
2x - x = - 11 + 10
x = -1
6. AB = 9x + 7
BC = -3x + 20
AC = 39
AB + BC = AC (segment addition postulate)
(9x + 7) + (-3x + 20) = 39 (substitution)
Solve for x
9x + 7 - 3x + 20 = 39
Collect like terms
9x - 3x + 7 + 20 = 39
6x + 27 = 39
Subtract 27 from both sides
6x + 27 - 27 = 39 - 27
6x = 12
Divided both sides by 6
6x/6 = 12/6
x = 2
The scientist can use only the angle x and the distance y to calculate the distance between the Earth and the Sun using the cosine function.
cos x = BC / y
Solving for BC
BC = y cos x
BC is the distance between the Earth and the Sun :D
The answer is -12 I believe