3log2+log5=?
A
log 30
B
log 40
C
3 log 7
D
log 13
Correct Answer: log 40
<math xmlns = "http://www.w3.org/1998/Math/MathML"><mn>3</mn><mo> </mo><mi>log</mi><mn>2</mn><mo> </mo><mo> + </mo><mo> </mo><mi>log</mi><mo> </mo><mn>5</mn><mspace linebreak = "newline"/><mo> = </mo><mi>log</mi><mo> </mo><msup><mn>2</mn><mrow><mn>3</mn><mo> </mo></mrow></msup><mo> </mo><mo> + </mo><mo> </mo><mi>log</mi><mo> </mo><mn>5</mn><mspace linebreak = "newline"/><mo> = </mo><mo> </mo><mi>log</mi><mo> </mo><mn>8</mn><mo> </mo><mo> + </mo><mo> </mo><mi>log</mi><mo> </mo><mn>5</mn><mspace linebreak = "newline"/><mo> = </mo><mo> </mo><mi>log</mi><mo> </mo><mfenced><mrow><mn>8</mn><mo> </mo><mo>×</mo><mo> </mo><mn>5</mn></mrow></mfenced><mo> </mo><mo> = </mo><mo> </mo><mi>log</mi><mo> </mo><mn>40</mn></math>