Question

From 7x2+5xy−3y2 subtract the sum of 2x2+3xy−5y2 and x2−7xy−4y2.

Answer 1

Answer:
`4x^(2) +9xy+6y^(2)`

Explanation:

First equation
`=`
`2 x^(2) +3xy-5y^(2)`

Second equation
`=`
`x^(2) -7xy-4y^(2)`

Third equation
`=`
`7x^(2) +5xy-3y^(2)`
`3x^(2) -4xy-9y^(2)`

Sum of the following of two valuable equation first and second

`(2x^(2) +3xy-5y^(2) ) + (x^(2) -7xy-4y^(2) )`

`(2+1) x^(2) +(3-7)xy+(-5-4)y^(2)`

`3x^(2) -4xy-9y^(2)`

Subtract third equation from the sum of two valuable expression

`(7x^(2) +5xy-3y^(2) ) - (3x^(2) -4xy-9y^(2) )`

`(7-3)x^(2) +(5-(-4))xy +(-3-(-9))y^(2)`

`4x^(2) +9xy+6y^(2)`