Question

`(-ab^(2) )/(14)+(ab^(2) )/(21)+(ab^(2) )/(18) -(ab^(2) )/(27)`

Please help asap

Answer 1

`\\ \sf\longmapsto (-ab^2)/(14)+(ab^2)/(21)+(ab^2)/(18)-(ab^2)/(27)`

• Taking LCM

`\\ \sf\longmapsto (-27ab^2+18b^2+21ab^2-14ab^2)/(378)`

`\\ \sf\longmapsto (-2ab^2)/(378)`

`\\ \sf\longmapsto (-ab^2)/(189)`

Answer 2

• 
  `-ab^2/189`

Explanation:

See the steps below:

• 
  `-ab^2/14 + ab^2/21+ab^2/18-ab^2/27=`
• 
  `ab^2(-1/14+1/21+1/18-1/27)`

Find the LCM of 14, 21, 18 and 27:

• 14 = 2*7
• 21 = 3*7
• 18 = 2*3*3
• 27 = 3*3*3
• LCM(14,21,18,27) = 2*7*3*3*3 = 378

Solve the fractions:

• 
  `-1/14 + 1/21 +1/18-1/27=\\`
• 
  `1/378(-27+18+21-14)=`
• 
  `1/378(-2)=`
• 
  `-1/189`

The answer is:

• 
  `-ab^2/189`