Hello from MrBillDoesMath!
Answer: b
Discussion:
7b + 3 - 4b = 3 - 3(b+4) =>
7b + 3 - 4b = 3 - 3b -12 =>
(7b - 4b) + 3 = -3b - 9 =>
3b + 3 = -3b -9 => Add 9 to both sides
3b + 12 = -3b -9 + 9 =>
3b + 12 = -3b => ( add 3b to both sides)
6b + 12 = 0 => (subtract 12 from both sides)
6b = -12 =>
b = -12/6 = -2
Thank you,
MrB
For this case we have the following equation:

We must clear the value of the variable "x" as a function of r, s and t:
If we multiply by "r" on both sides of the equation we have:

If we subtract "t" on both sides of the equation we have:

If we divide by "2" on both sides of the equation we have:

Thus, the value of the variable "x" is:

Answer:

Answer:
C
Step-by-step explanation:
Evolution is where organisms have developed over time from simple to complex. Therefore we can rule out D because older rock layers should have simple organisms and A because new rock layers should have more complex organisms. The previous organisms will be unlike those of today, therefore the correct answer is C.
Hi,
<span><span><span><span>4n</span>+3</span>+<span>2c</span></span>+4</span><span>=<span><span><span>(<span>2c</span>)</span>+<span>(<span>4n</span>)</span></span>+<span>(<span>3+4</span>)</span></span></span><span>=<span><span><span>2c</span>+<span>4n</span></span>+7</span></span>Hope this helps you.