Assume a is not divisible by 10. (otherwise the problem is trivial).
<span>Define R(m) to be the remainder of a^m when divided by 10. </span>
<span>R can take on one of 9 possible values, namely, 1,2,...,9. </span>
<span>Now, consider R(1),R(2),......R(10). At least 2 of them must have the sames value (by the Pigeonhole Principle), say R(i) = R(j) ( j>i ) </span>
<span>Then, a^j - a^i is divisible by 10.</span>
7(x+2) = 35
Use the distributive property:
7x + 14 = 35
Subtract 14 from each side:
7x = 21
Divide both sides by 7:
x = 21 / 7
X = 3
The answer is C. 3
11/15-2/5
Multiply 2 and 5 to get a common denominator of 15
11/15-6/15
=4/15
Answer:739,000
Step-by-step explanation:
2
x
2
−
5
x
−
3
=
0
Step 3: Factor left side of equation.
(
2
x
+
1
)
(
x
−
3
)
=
0
Step 4: Set factors equal to 0.
2
x
+
1
=
0
or
x
−
3
=
0
x
=
−
1
2
or
x
=
3
Answer:
x
=
−
1
2
or
x
=
3
