39 x 5 = (30 x 5) + (9 x 5) = 150 + 45 = 195
He did not change the sign of operation when 28 crossed the equals sign.
The answer would be 314.16 square cm
Hope this helps! :)
Answer:
whats the question?
Step-by-step explanation:
Answer:
3n^2+9+5n^4+55n
Step-by-step explanation:
Steps
$\left(3n^2+9+5n^4-3n\right)+\left(-9n\left(-7\right)-5n\right)$
$\mathrm{Remove\:parentheses}:\quad\left(a\right)=a,\:-\left(-a\right)=a$
$=3n^2+9+5n^4-3n+9n\cdot\:7-5n$
$\mathrm{Add\:similar\:elements:}\:-3n-5n=-8n$
$=3n^2+9+5n^4-8n+9\cdot\:7n$
$\mathrm{Multiply\:the\:numbers:}\:9\cdot\:7=63$
$=3n^2+9+5n^4-8n+63n$
$\mathrm{Add\:similar\:elements:}\:-8n+63n=55n$
$=3n^2+9+5n^4+55n$
Answer:
Step-by-step explanation:
3ab + 7a² + 2b² - (7a² - 4ab + 2b²) = 3ab + 7a² + 2b² - 7a² + 4ab - 2b²
Now combine like term. Like terms have same variable with same power.
= <u>3ab + 4ab</u> <u>+ 7a² - 7a²</u> + <u>2b² - 2b²</u>
= 7ab
