what are the answers to the following problems:

Problem 1: 3(2i+7)=6i+21
Problem 2: 3i+5=2i−7
Problem 3: 3i+2i−7=18
Problem 4: 3(2i−7)=15
Problem 5: 3i+5=3i+7

1 answer

Let's solve each problem step by step.

Problem 1:
\[3(2i + 7) = 6i + 21\]

Distributing on the left side: \[6i + 21 = 6i + 21\]

Both sides are equal, so the equation holds for all values of \( i \). The answer is true for all \( i \).


Problem 2:
\[3i + 5 = 2i - 7\]

Subtracting \(2i\) from both sides: \[ 3i - 2i + 5 = -7 \] This simplifies to: \[i + 5 = -7\]

Subtracting 5 from both sides: \[i = -12\]

So, the solution is \(i = -12\).


Problem 3:
\[3i + 2i - 7 = 18\]

Combining like terms: \[5i - 7 = 18\]

Adding 7 to both sides: \[5i = 25\]

Dividing both sides by 5: \[i = 5\]

So, the solution is \(i = 5\).


Problem 4:
\[3(2i - 7) = 15\]

Distributing on the left side: \[6i - 21 = 15\]

Adding 21 to both sides: \[6i = 36\]

Dividing both sides by 6: \[i = 6\]

So, the solution is \(i = 6\).


Problem 5:
\[3i + 5 = 3i + 7\]

Subtracting \( 3i \) from both sides: \[5 = 7\]

This is not true, so the equation has no solution.


To summarize:

  • Problem 1: True for all \( i \)
  • Problem 2: \( i = -12 \)
  • Problem 3: \( i = 5 \)
  • Problem 4: \( i = 6 \)
  • Problem 5: No solution.